Lesson 8-1

La Merc is a festival that takes place in Barcelona, Spain. P

It is held every September in honor of the Virgin of Mercy, one of the city's main saints. P

There are hundreds of free events all across the city, but three special ones should not be missed. P

Seeing a castell is the first thing you should do. P

Castells are tall towers built out of people! P

These people stand on each other's shoulders and make towers that are up to 10 people tall. P

Castells are amazing to look at but dangerous to make. P

Audiences watch nervously as small children climb to the top. P

Next, you should go watch the correfoc, also known as the fire run. P

It is a parade with fireworks, drummers, and dancers. P

People dress as devils and monsters and use special sticks to shoot fire into the air. P

If you get close, be careful! You need to protect your skin, hair, and eyes from the "fire rain"! P

Besides the correfoc for adults, there is also a safer one for children. P

Finally, the Cavalcada de la Merc is the perfect event for kids. P

People march through the crowds carrying giant figures as musicians beat drums and blow pipes. P

Other events include street theater, concerts, and dancing. P

Come and enjoy La Merc! P

Lesson 8-2

The firework master's workshop was full of activity and noise because the lantern festival was in two weeks. P

All of the fireworks had to be ready for a special show. P

Ming was given a very important job. P

Master Yi asked him to create a special firework. P

It was to be the highlight of the show. To Ming, it was a terrible burden. P

Every year, the fireworks were different from the year before. P

Even worse, the emperor had seen them all. P

Ming's firework needed to be something no one had seen before. P

That worried him a lot. Everyone watched with curiosity as Ming worked. P

He ran back and forth to the storeroom getting powders and metals. P

Then, he ground the metals down into small pieces. P

He worked late into the night after everyone else had gone home. P

The next night, Ming called everyone out into the yard behind the workshop. P

He lit a rocket as they all looked on. P

After a few seconds, it shot up into the sky. P

First, there was an explosion of red. P

From this, five fireballs flew out. P

Each one exploded into a different color. Everyone clapped and cheered. P

Master Yi smiled and put his hand on Ming's shoulder. P

The emperor would be very pleased with Ming's firework. P

Lesson 8-3

It is important to exercise so that you can stay fit. P

Two of the best kinds of exercise are walking and running. P

Walking and running are very simple, cheap, and healthy. P

You can do them alone, anywhere, at any time. P

You just need a good pair of running shoes. P

Both exercises make your heart stronger, and they're good for your bones and muscles too. P

Running helps you lose weight more quickly. P

When running, people move faster and work harder. P

That means that running burns more calories than walking. P

Also, running is better for busy people. P

To get results similar to running, people have to walk longer or more often. P

But walking can be a better choice for heavy or old people. P

Running can put a lot of stress on people's joints, so it can easily hurt these parts. P

Walking, however, causeless stress than running. P

It doesn't hurt weak hips, knees, or ankles. P

Both walking and running are great kinds of exercise. P

Either one will make you healthy, but everyone should choose the right exercise for themselves. P

So, what are you waiting for? Get moving! P

Lesson 8-4

There once was a rabbit. He loved to eat sweet clover until he was full. P

Then, he would take a long nap in the shade. There was also a wolf. P

He often came around and found the rabbit lying under a tree. P

However, the rabbit could run much faster than the wolf. P

He always escaped into the thick bushes, leaving the wolf behind licking his lips. P

As time went on, the rabbit couldn't run as fast as housed to. P

He was getting slower and slower because he washout of shape. P

Every time he saw the wolf, the rabbit decided to change. P

He wanted to stop eating so much and start being more active. P

But exercising was really difficult. P

It wasn't fun at all! Each day, the rabbit would promise to start the next day. P

The next day, he would do the same thing. P

He didn't change a bit. The wolf, on the other hand, worked hard. P

He practiced running faster and faster. P

Before too long, he could run faster than the lazy rabbit. P

Then one day, the rabbit wasn't quite fast enough, and the wolf enjoyed a delicious meal. P

Lesson 8-5

You've probably learned in science class that clouds have different names. P

Did a scientist make these names? No! It was Luke Howard, a normal man who loved to watch clouds. P

Howard was born in London in 1772. P

As a child, he was interested in the weather. P

He became a pharmacist when he grew up, but he still loved watching the weather and recording what he saw. P

In 1802, Howard presented an essay about classifying clouds. P

In it, he classified them into three categories using Latin names. P

Cirrus clouds are long and thin. Their name means "a piece of hair. P

"Cumulus clouds are big and puffy. Their name means "heap. P

"Last, stratus clouds are spread out like a blanket. Their name means "layer. P

"Howard also described clouds using combinations of these three names, P

because clouds often change between categories. P

Finally, housed the term "nimbus" to describe any kind of cloud that produces rain. P

No one had ever succeeded in classifying clouds like Howard. P

Soon, scientists in Europe began using his names. P

Howard continued his daily observations of the weather. P

He later discovered that urban areas are warmer than the countryside. P

This is now known as the "heat island effect." P

Although he wasn't a professional scientist, Luke Howard greatly influenced the science of observing the weather. P

Plus, his cloud names are still used all around the world! P

Lesson 8-6

Long ago, Our Mother chose a human to put the stars into the sky. P

She gave this human a jar full of stars. P

Coyote was very curious about this jar and wanted to look inside it. P

However, Our Mother knew that Coyote always caused trouble. P

For that reason, she told him, "Don't touch that jar!" P

Soon, the human was carefully making shapes in the sky and naming each one. P

He used three stars to make the Pot Rest Stars and seven to make the Shield Stars. P

Everyone stopped to look up at the shapes in the sky. P

They were all amazed by how beautiful the shapes were. P

At that moment, no one was watching Coyote, so he went over to the jar. P

More curious than ever, he lifted the lid just a little bit. P

In an instant, the stars burst out and flew upwards. P

They raced here! They shot there! P

They stuck in the sky with no order at all! P

And that is why only a few groups of stars have a name and a shape. P

The rest are spilled all over the sky. P

Lesson 8-7

Yawning is very common. Everyone yawns. P

Babies even yawn before they're born. P

However, scientists don't know exactly why we yawn. P

One idea is that we yawn because we need more fresh air. P

This helps us to understand why we yawn in groups. P

When many people are together, the air isn't fresh. P

Because of that, we yawn to get more fresh air. P

However, a study showed that this may not be true. P

A scientist gave people less fresh air, but they didn't yawn more. P

Another idea is that yawning shows you are bored. P

In another study, a scientist showed music videos to some students and an unchanging screen to others. P

He found that the first group yawned less. P

However, this doesn't explain why Olympic athletes sometimes yawn before they compete. P

Surely they can't be bored. The latest idea is that yawning cools down the brain. P

When we are tired or sleepy, our brains get hotter and don't work as well. P

Yawning brings in cool air. This cools down our brains and helps them work better. P

This idea might be true. A scientist put cold packs on people's foreheads. P

They yawned less often. Scientists still need to study yawning more to fully explain it. P

Which idea about yawning do you believe is true? P

Lesson 8-8

In English class, the teacher was talking about the homework. P

She wanted everyone to prepare a speech and give it in front of the class. P

Roger's eyes grew wide. He was too shy to speak in front of the whole class! P

He worried about it for the rest of the day, but he decided to try his best. P

He worked hard on preparing his speech. P

Then, he practiced it many times. P

The night before the speech, Roger couldn't sleep. P

He kept worrying about the next day. P

He read his speech overhand over. P

It was two a.m. when he finally fell asleep. P

The next day, it was Roger's turn first. P

He read the first two lines of his speech. P

Then, he yawned. He read a bit more, and he yawned again. P

Some kids in the back of theorem laughed. Even the teacher laughed. P

Roger's face turned bright red. He couldn't continue, so he sat down. P

Then, the teacher talked to Roger. She told him that he was doing fine. P

He had clearly worked hard. She wanted everyone to clap for Roger. P

Then, she asked him to continue. Roger felt better and started his speech over. P

This time, he gave a great speech. P

Lesson 8-9

Have you ever seen or played an organ? This instrument looks very similar to a piano. P

Both of them have keyboards with black and white keys. P

They also have pedals. However, the two have more differences than similarities. P

First, their sizes are different. Organs are much bigger than pianos. P

Pianos have three pedals and one keyboard, P

but organs usually have many pedals and one to five keyboards. P

Organs also have long pipes attached to them. P

Second, the way they make sound is different. P

Pianos use small hammers and metal strings to make sound. P

When you press a piano key, a hammer hits a string. P

However, organs make sound by using pipes. P

When you press an organ key, airs pushed through a pipe. P

Unlike piano pedals, each organ pedal can also make a different sound. P

Finally, how long the sound lasts is different. P

Pianos make sound for only a few seconds. P

After you press piano's keys, the sound dies away quickly. P

However, organs make sound for an indefinite amount of time. P

This sound lasts as long as you hold their keys or pedals down. P

Lesson 8-10

Pan was the Greek god of shepherds. P

He loved being in nature and having fun with the animals. P

He looked very strange though. P

Unlike most people, he had the horns, ears, legs, and tail of a goat! P

One morning, Pan was walking through a forest when he saw a beautiful nymph named Syrinx. P

Instantly, he fell in love and ran towards her. P

Of course, Syrinx ran away because Pan scared her. P

Through the woods she ran and ran until she came to a river. P

She couldn't cross it, so she stopped. P

Then, she saw Pan coming. P

She was afraid that he would catch her, so she called out, "Water nymphs, please save me!" P

As Pan reached the river, the water nymphs answered Syrinx's prayer. P

They turned her into some reeds, causing Pan to sigh in sadness. P

His sighs passed over the reeds. P

They made beautiful sounds that reminded Pan of Syrinx. P

Then, he had an idea. He cut the reeds up into different sizes and tied them together. P

In this way, he created the first panpipe. P

From then on, Pan played the panpipe everywhere he went to remember the beautiful Syrinx. P

Lesson 8-11

On most bikes, riders sit above the wheels. P

The pedals are below the seat. P

But there is a different kind of bike called sit-back bike. P

On it, riders lie back in a low chair. P

Their legs are stretched out since the pedals are in front. P

Because of these features, sit-back bikes have some advantages over normal ones. P

Sit-back bikes are more comfortable than normal bikes. P

Riders sit in a more relaxed position, so their necks and backs don't feel as sore as those of normal bike riders. P

If you use one of these bikes, you will enjoy riding it all day long! P

Riders can also go faster on sit-back bikes. P

On normal bikes, the rider's whole body faces the wind. P

But on a sit-back bike, the wind hits a smaller area of the rider's body. P

For this reason, sit-back bikes move through the wind faster. P

However, sit-back bikes have several disadvantages. P

For one thing, riders can't climb hills as easily. P

This is because they can't stand up or lean forward. P

Also, balancing is harder on sit-back bikes. P

Riders can't move their upper bodies to stay balanced. P

Luckily, these problems just take some time to get used to. P

At first, sit-back bikes look and feel strange. P

However, they have many advantages, and getting used to them is definitely fun. P

Lesson 8-12

Pietro worked for a movie theater. P

He rode his bike around the city and put-up posters. P

He then gave all the money he earned to his parents. P

One day, Petro was riding his bike and putting up a lot of posters. P

He was tired and thirsty, so he stopped and went into a store. P

When he came out, his bike was gone! P

He looked everywhere, but he couldn't find his bike. P

It had been stolen! Now Pietro couldn't do his job. P

What would his family do? He walked home sadly. P

Then, something caught his eye. P

It was a shiny red bike leaning against a wall. P

No one was around. He could take the bike and solve his problem. P

Pietro thought about it. The bike belonged to someone else. P

That person probably also needed it. P

Taking it would be wrong, so he continued going home. P

The next day, Pietro went to work. P

When he got there, the owner of the theater wanted to talk to him. P

His parents had called her about his problem. P

She said that, because he was a good worker, she had bought him a new bicycle! P

Lesson 8-13

Henri Rousseau was born in France in 1844. P

As a child, he was talented at drawing and music. P

However, when he got older, Rousseau took a job at the Paris Customs Office. P

While he worked there, he painted as a hobby. P

In 1893 at the age of 49, he retired and focused on his art. P

Rousseau enjoyed painting jungle scenes, but he had never been to the jungle. P

Instead, he visited a garden and zoo in Paris to paint plants and animals. P

He also looked at animal pictures in books. P

These helped him use his imagination to make up his own jungles. P

Rousseau taught himself how to paint, so his style was unique. P

The images were flat and childlike, and the colors were bright. P

Most art critics disliked his work. P

One even said that it looked like Rousseau painted with his feet. P

However, some artists loved it. P

Pablo Picasso and Wassily Kandinsky were both fans of Rousseau's work. P

Few of Rousseau's paintings were sold while he was alive. P

After he died in 1910, however, they became very popular. P

Now his artwork is known by people around the world, and he is considered a genius. P

Lesson 8-14

My name's Helen, and I'm a teacher who loves art. P

My son Paul is a famous artist, but he's only two! P

Paul began painting very early. P

I would put paper and paints in front of him. P

He just used his hands and fingers to paint. P

His paintings showed a lot of talent. P

Of course, I thought they were what you'd expect from a little child. P

They were wild and bright with big splashes and messy lines everywhere. P

However, I soon discovered that they looked a lot like paintings by famous artists. P

I showed Paul's paintings to my friend Sarah, who's an art critic. P

She wanted to see what other people thought and posted some of his paintings on her website. P

She also gave them interesting titles and descriptions. P

Within a few days, there was a lot of excitement on the website. P

People loved Paul's artwork and wrote comments about it. P

Then, Sarah took some of Paul's paintings to an art gallery. P

The gallery owner was amazed. P

He even asked to have an exhibition of Paul's work. P

When Sarah told him how old Paul was, he was shocked. P

Paul's paintings are good, but I never thought this would happen! P

Lesson 8-15

Insects are very small. Surviving is difficult for them, so they must be very clever. P

One way they survive is by looking like something else. P

Katydids are a kind of grasshopper. P

They have green, leaf-shaped wings that are covered in veins. P

When predators are near, katydids stop moving. P

If they surround themselves with leaves and stay completely still, they look like part of the plant. P

That way, the predators can't find them easily. P

Hemeroplanestriptolemus caterpillars use a different method. P

They have two large spots that look like eyes on one end of their bodies. P

When birds approach, this end gets bigger and becomes diamond shaped. P

In this way, it looks like a snake with its eyes wide open. P

The caterpillars even move like attacking snakes, so the birds get scared away. P

Orchid mantises are another kind of interesting insect. P

They are pink and white with legs shaped like flower petals. P

That makes them look like flowers. P

Smaller insects think the mantises are real flowers, so they come over to eat some nectar. P

This makes it easier for the mantises to catch them. P

There are many other clever creatures that pretend to be something else. P

Can you think of any? P

Lesson 8-16

Long ago, Beetle lived in the forests of Brazil. P

She was small and gray. Her neighbor, Agouti, was big and brown. P

He wore a shiny fur coat. "Beetle, you aren't as pretty as me, "Agouti teased. P

"You are ugly and plain." Every day, Parrot heard Agouti teasing Beetle. P

"This isn't right," he thought. P

One day, he finally said, "Agouti! Listen up! You will race against Beetle. P

The winner can choose a coat of any color. P

" Agouti liked that idea, so the race started. P

Parrot said, "Go!" and Agouti ran as fast as he could. P

"I can run fast," Agouti thought, P

"but Beetle walks slowly. I'm going to win!" P

Soon, he saw the finish line. "I win!" he yelled. P

But wait! Beetle was already there! P

"How did you run so fast?" Agouti cried. P

"I didn't run. I flew," Beetle answered. P

"I never knew you could fly!" said a very angry Agouti. P

Parrot laughed. "You only saw Beetle's plain color. P

You didn't see her talents. Don't judge others by their looks." P

Agouti was embarrassed. P

He ran and hid in the bushes while Beetle chose a beautiful gold-and-green coat. P

Today, her bright colors still shine in the sun. P

Lesson 8-17

Mother Teresa was born in 1910. P

She grew up in a kind, religious family. P

When she was young, she felt the call of God to be a missionary. P

In 1928 when she was 18, she left home to become a nun. P

She joined the Sisters of Loreto in Ireland. P

Then in 1929, she arrived in Calcutta, India, as a missionary to teach at a high school there. P

On the city streets, she saw many poor and sick people. P

Then she felt God call to her again. P

She knew she had to help them, so she talked to the church leaders. P

They let her leave the school to start taking care of the poor. P

Mother Teresa started her own work teaching very poor children in 1948. P

At first, her life was difficult. She did not have much money or support. P

But soon, other people began helping her. P

In 1950, she started a group called the Missionaries of Charity. P

She and some other nuns gave food, shelter, and medicine to many poor and sick people. P

For her work, Mother Teresa won many awards. P

They include the 1979 Nobel Peace Prize. P

Mother Teresa died in 1997. Many people still love her though. P

Now over 5,000 nuns are in her group. P

They continue to help poor people all over the world. P

Lesson 8-18

Yesterday, a nurse came to our class. P

She told us that she cared for sick children. P

These children are fighting diseases. P

The nurse asked us to draw a picture on a wall in the hospital to cheer them up. P

Some of my classmates were worried because they weren't good at art, but she said it didn't matter. P

Today, we went to the hospital with our teacher. P

The sick children there looked unhappy. The wall in their room was dull. P

It made the whole room look sad too. P

We decided that we had to do our best to help them. P

Even the kids who weren't good at art did something important. P

They played with the sick children. Other kids had different skills. P

Harper and Mike drew a plan for the wall painting on some paper. P

Nate and I sketched it on the wall in pencil. P

Then, Michelle and Amy painted the outlines. P

We all worked together to fill in the colors. P

Our picture looked great. It made the room look happier. P

The nurse gathered all the sick kids around. P

They looked at our picture and smiled. P

Then, everyone clapped. We felt really proud of our work. P

Lesson 8-19

Did you know the size of air changes with heat or cold? P

Here's a fun trick that uses this fact. P

You can put an egg into a bottle. P

The opening of the bottle is smaller than the egg, but the egg goes in. Isn't it amazing? P

First, get the materials you need: P

an egg, some matches, and a glass bottle with a long, narrow neck. P

Make sure the opening of the bottle is a bit smaller than the egg. P

Boil the egg. Then, put it under cold water and peel it. P

Put the bottle on the table. Next, light some matches and put them in the bottle. P

Then, quickly put the egg on top of the bottle. P

Soon, it will go in! Why this happens is simple. P

The matches heat up the air in the bottle. P

The air becomes larger, and some leaves the bottle. P

Then, you close the opening with the egg. P

When the matches go out, the air cools and becomes smaller. P

This makes the pressure of the air inside the bottle lower than the pressure outside the bottle. P

The higher outside pressure then pushes the egg into the bottle. P

Lesson 8-20

My brother Etienne and I were fascinated with things that could float in the air. P

One day in November 1782, I wondered if a cloth bag could float. P

To find out, I lit a fire under it. P

Amazingly, it rose up! I wrote to Etienne right away to tell him the news. P

Together, we started to make larger bags, or balloons, and flew them outside. P

On June 4, 1783, we flew one of our hot air balloons in front of other people for the first time. P

Everyone was amazed and even a little scared by it! P

Next, we decided to put a sheep, duck, and rooster in a basket attached to a balloon to see if going up high hurt them. P

They were the world's first hot air balloon passengers. P

King Louis XVIand Queen Marie Antoinette watched this balloon fly on September 19. P

Both of them were very impressed by it. P

Later, we sent a person up in a balloon on October 15. P

However, the balloon was still tied to the ground by a rope. P

Finally, two people flew in one of our balloons on November21 without any ropes! P

Everyone watching cheered loudly and congratulated us on how far our balloon flew. P

Justa year after my first discovery, we, Joseph and Etienne Montgolfier, had made history. P

Lesson 8-21

Dugongs and manatees are similar marine mammals. P

Neither animal ever leaves the water, even to give birth. P

Also, the babies of both animals feed on their mothers 'milk. P

Both dugongs and manatees are unable to breathe underwater, so they must rise to the surface to get air. P

They even look alike, with large bodies and wide, flat tails. P

Both animals sometimes lift their upper bodies out of the water by "standing" on their tails. P

In the past, this behavior sometimes caused sailors to mistake them for mermaids! P

Despite these similarities, it is possible to tell the two animals apart. P

The main differences are in their tails and snouts. P

Dugongs have snouts that point downward, whereas manatees have snouts that stick straight out. P

Also, dugongs' tails are forked like a whale's. P

Manatees' tails, on the other hand, are rounded. P

Both animals live in warm, shallow water and eat sea plants all day. P

This is probably why they are nicknamed "sea cows. P

"However, manatees live in the Caribbean Sea, the Amazon River, and West Africa, P

while dugongs are usually found near East Africa, South Asia, and Australia. P

Also, dugongs only live in salt water, but some manatees only live-in fresh water. P

Other manatees move between salt water and fresh water. P

In the past, there were many manatees and dugongs in the world. P

Unfortunately, lots of them died because of human activities. P

These days, some groups are working to save them. P

If we don't keep protecting them, soon they might only exist in stories, just like mermaids. P

Lesson 8-22

One morning, the sun got caught in a tall tree. P

It couldn't rise, so the world stayed dark. P

Soon, the animals began to worry. P

They decided to go and look for the sun. P

Eventually, a little brown squirrel found the sun stuck in the tall tree's branches. P

It looked tired and weak. "Please help me get free," said the sun. P

Quickly, the squirrel began to chew away the branches. P

As he chewed, the sun got brighter and hotter. P

In the heat and light, the squirrel's fur turned black, his tail began to burn, and he started to go blind. P

However, he kept chewing. At last, the squirrel chewed through the final branch. P

The sun was free! It started to rise, and daylight came back to the earth. P

All the animals were happy again, but the squirrel was sad. P

His beautiful tail had burned up, and his fur had all turned black. P

Worst of all, he couldn't see a thing. P

The sun looked down and felt sorry for the squirrel. P

"You helped me," it said, "so I will grant you a wish." P

"Well, I always wanted to fly," the squirrel said. P

The sun nodded. "From now on, you will fly. P

You will also see and hear everything around you. P

However, you must wake up after I say goodbye to the world." P

And that is exactly what happened. At nighttime, the squirrel could see and fly. P

He became the first bat. P

Lesson 8-23

The Louvre in Paris, France, is the most famous art museum in the world. P

However, it was not always an art museum. P

At first, the Louvre was a fort. P

In the Middle Ages, Paris was one of the biggest cities in Europe. P

Its ruler, Phillip II, was afraid that his enemies might attack it. P

To protect the city, he built the Louvre outside of it in 1190. P

Over the years, the city grew beyond the Louvre, so it stopped working as a fort. P

Then, Charles V turned the Louvre into a beautiful palace. P

In 1364, he started to add new buildings, a garden, and a library. P

Later on, many kings after him built more as well. P

In 1682, Louis XIV moved to a new palace, Versailles. P

After that, the Louvre became an art gallery and school. P

Artists studied there and held exhibitions once every year or two. P

Finally, the Louvre became a public art museum. P

There was a revolution, and the royal family lost its power. P

The museum opened in 1793 and showed the royal family's art to the public. P

It grew as France got more art from around the world, and many new display rooms were added. P

The Louvre now has over 380,000 works of art. P

Two of the most famous are the Mona Lisa and the Venus de Milo. P

Every year, millions of people visit the museum to enjoy its history and art. P

Lesson 8-24

What a tiring day! My family and I just got back from touring around the Alhambra in Granada, Spain. P

The Alhambra is a historical site with palaces, gardens, and even a fort. P

Most of it was built by the Muslims who ruled southern Spain in the 1200s and 1300s. P

If you ever go to Spain, it is definitely worth visiting. P

The Alhambra is full of beautiful architecture, but the most beautiful buildings of all are the three Nasrid Palaces. P

There are many rooms in them. P

Out of all these rooms, the largest is the Hall of the Ambassadors. P

It is decorated in an absolutely amazing way. P

Leaf patterns, Arabic writing, and lots of shapes cover every inch of its walls. P

Additionally, its square dome ceiling is made up of more than 8,000 pieces of cedar wood. P

It looks like a starry sky! Outside, the palaces have lots of open areas. P

My favorite was the Courtyard of the Lions. P

It has a stone fountain with 12 lion sculptures in the middle and124 marble columns along the edges. P

After seeing the Nasrid Palaces, we went to the Generalife, which is the Alhambra's summer palace. P

There is water everywhere in the Generalife's gardens. P

There are lots of flowers, trees, and other plants as well. P

Walking through them is very relaxing. P

Unfortunately, we ran out of time and had to leave the Alhambra. P

But I already can't wait for my next visit! P

Lesson 8-25

A lot of people enjoy eating popcorn. P

It is very popular at the movies. P

Do you know how this delicious snack pops? P

Corn kernels, like other grains, have water inside. P

When you heat them up, their water becomes steam. P

Steam needs much more space than water. P

To find enough space, it must break out of the corn. P

That breaking is the"pop!" P

Popcorn will only pop right when two things are correct. P

First, around 13.5 percent of the kernel must be water. P

This amount is necessary to make enough steam. P

If there is less water, there won't be enough steam to pop the kernel. P

However, too much water will make too much steam. P

All this steam breaks the kernel too soon, which means that it doesn't get cooked. P

It just becomes hard and chewy. P

Second, the kernels must not be cracked. P

Even a small crack will let the steam escape as soon as it forms. P

The pressure won't get high enough, so the kernel won't pop. P

Can other grains pop like corn? Usually they can't because corn is special. P

It has a hard outer skin which doesn't have any holes. P

This skin holds in the steam until the kernel pops open. P

Most other grains, like rice and wheat, don't have this hard, hole-free skin. P

Only grains that have it can pop the way corn does. P

Good popcorn is light and fluffy. P

Making it is quite hard, but the result is delicious! P

Lesson 8-26

There once was a port city called Stavoren. P

Its harbor was always crowded with ships, and the merchants of the city grew rich. P

Of these, the wealthiest was the Lady of Stavoren. P

Unfortunately, she was also the greediest and most arrogant. P

More than anything, she wanted to own the most precious thing in the world. P

The lady sent one of her ship captains out to search for the world's greatest treasure. P

When he returned, she eagerly asked him, P

"What have you brought me? Silver? Gold? Jewels?" P

The captain answered, "None of those things. P

I have brought you wheat!" Indeed, the ship was full of grain. P

For a second, the lady was shocked. P

Then she angrily said, "What do you think I am, a fool? This is worthless to me. P

Drop it into the water!" The captain begged her not to do it. P

"Nothing is more precious than the grain that feeds us. P

If you throw it away, something terrible will happen!" P

But the lady laughed and did it anyway. P

A few weeks later, the captain's prediction came true. P

The wheat grew at the mouth of the harbor and trapped a lot of sand, making a huge hill of sand under the water. P

Because of this, ships could no longer enter Stavoren, and all of the merchants lost their wealth. P

Of these, the one who lost the most was the lady. P

She had to beg for bread the rest of her life. P

Lesson 8-27

A lot of people have trouble with money. P

Even though they don't have much of it, they buy things anyway. P

Saving money isn't easy, but you can learn how at a young age. P

Just follow these steps! First, set saving goals. P

These are the amounts you want to save. You may want to buy something. P

Find out the cost and decide when you want to buy it. P

Make your saving goals very specific. P

Next, add up all the money you regularly get. P

Maybe you get some from your parents. P

Or maybe you get some by helping people. P

Find the total amount of money. P

Then, you'll need to find out how much money you spend. P

Make a list of everything you spend in a week or a month. P

Afterward, see how much you can save. P

You can do this by subtracting the money you spend from the money you make. P

Maybe it isn't enough. P

In that case, check the list for things you don't need and stop buying them. P

Now you can start saving money. A good way is to open a bank account. P

Ask your parents for help. P

They can choose a good savings account and help you put your money in it. P

Soon, the bank will pay you a small amount of money for leaving it there! P

It might take some time, but it'll feel great to reach your goal. P

Lesson 8-28

There once was a miser. He hated to spend any money at all. P

Instead, he bought a big piece of gold and buried it in his garden. P

Every day, he would dig up the gold and look at it. P

This always made him very happy. P

One day, a thief saw the miser digging up his gold. He decided to steal it. P

When nighttime came, he dug up the treasure and ran away with it. P

The next day, the miser came back to look at his gold. P

However, he couldn't find anything in the place he had buried it. P

There was nothing but an empty hole. P

He cried out loudly, and one of his neighbors came over to help him. P

The miser explained to him what had happened and showed him the empty hole. P

"Did you ever spend any of it?" asked the neighbor. P

"No, "said the miser, "I would only dig it up and look at it." P

"So you just looked at it and didn't use it at all," said the neighbor. P

"From now on, why don't you put a rock in the hole and pretend that it is your gold? P

Then you can be just as happy as you were before. P

After all, it will be as useful as the gold you never spent. P

Lesson 8-29

Many people dream of living in space because floating around in low gravity looks like fun. P

However, low gravity actually makes life difficult. P

Astronauts must do everyday things in new ways. P

One problem is keeping clean. Water doesn't fall to the floor in low gravity. P

Instead, it moves around in drops. That means that astronauts can't take showers. P

They have to bathe with wet towels or small bags filled with water. P

They also use these bags to wash their hair. P

They carefully squeeze some water from the bag into their hair, P

add some special shampoo, rub it in, and then dry off with a towel. P

Exercising is very important in space. P

Because there is little gravity, astronauts don't have to work hard to move around. P

Soon, their muscles and bones get very weak. P

To stay healthy, they need to exercise about two hours a day. P

They use exercise equipment like treadmills, but they must tie themselves to it. P

If they didn't, they would just float away from it. P

Eating is done differently too. Since there is little gravity, everything floats. P

Because of that, the trays must be fastened to something that doesn't move like the wall. P

The astronauts also must be careful with their food since small pieces could float around and damage the spacecraft. P

For this reason, they usually eat wet or sticky foods that don't produce crumbs. P

They can also only use salt and pepper in liquid form. P

Lesson 8-30

At dinner, my parents told me about my birthday present. P

They had signed me up for a space camp. P

It was located in Huntsville, Alabama. P

I wasn't interested in space, so I didn't want to go. P

When we arrived at the camp, a guide told us about the program. P

Later in the week, we would learn how to fly a space shuttle. P

But that day, we were going to try out a simulator. P

It was all really boring. We walked to a large building. P

A trainer told us about the simulator. P

It was a chair hanging from several springs. P

In it, people can experience the feeling of low gravity. P

Just like on the Moon, people only weigh one sixth of their usual weight. P

The Apollo astronauts even practiced walking on the Moon with this type of simulator. P

The trainer chose me to go first. I got into the seat and pushed off lightly. P

Then, I went way up in the air! It was like I weighed nothing at all. P

There are three movements that make walking on the Moon easier. P

I tried them all. First, I hopped forward like a bunny. P

Then, I moved with large steps from side to side. P

I also slowly jogged forward. It was a lot like walking on the Moon. P

Soon, it was someone else's turn. P

I had to get off, but my heart was still racing. P

Space camp suddenly wasn't so bad after all. P

Lesson 8-31

In the 1930s, many people, including thousands of Jews, P

left Germany and Austria to get away from the Nazis, terrible acts. P

They went to other European countries, such as Czechoslovakia. P

In December 1938, Nicholas Winton, an English stockbroker, P

visited a friend in Prague, Czechoslovakia, who was helping refugees there. P

It was obvious that the Nazis would invade Prague soon, so those people were in great danger. P

Winton had heard about efforts to help Jewish children escape from Germany and Austria. P

He decided to do something similar in Czechoslovakia. P

First, he took applications from refugee parents. P

Next, he found British families willing to take care of the children. P

He also started raising money to pay for the transportation. P

On March 14, 1939, the first train carrying these children left Czechoslovakia. P

Over the next five months, seven more trains carried children to safety. P

There was a ninth train carrying 250more children, P

but World War II in Europe started on the day it was supposed to leave. P

Sadly, it was no longer possible to cross Czechoslovakia's borders. P

Despite this, Winton succeeded in rescuing a total of 669 children. P

Winton, however, was a humble hero. P

He rarely talked about what he had done for the children, so few people knew. P

It wasn't until 1988 that the world found out. P

He received many honors from the U.K. and the Czech Republic. P

Nicholas Winton died in 2015, but his brave actions will never be forgotten. P

Lesson 8-32

There was once a young boy named Abdul. P

His house was close to the railroad, so he walked home from school along the tracks. P

Every day, a train with many passengers would pass by him. P

One day, Abdul saw something shocking. P

Part of the tracks was bent. Soon, a train would come. P

Abdul knew its wheels would come off the bent tracks. P

He worried that many people would get hurt. P

Abdul looked for someone to help, but no one was around. P

He had to do something, and it had to be fast! The train was coming. P

Abdul had an idea. He grabbed a stick and tied his red scarf to it. P

Then, he ran down the tracks toward the train. P

He waved the red flag wildly above his head. P

The driver saw Abdul and the fear on the boy's face. P

He knew something was wrong and pushed hard on the brakes. P

There was a loud, terrible sound. Then, the train began to slowdown. P

It stopped just in time. Abdul had saved the lives of hundreds of people! P

The story spread throughout the country. P

People from a TV station came to his town to make a program about him. Abdul was a hero! P

Lesson 8-33

The Arctic and Antarctica are located at the north and south ends of the earth. P

They are similar in many ways. P

For example, they are both so dry that they are considered deserts. P

Plus, both places have two seasons: a cold summer and a colder winter. P

There is a big difference between them, though. P

The Arcticis made up of a frozen ocean and parts of the continents that surround it. P

Antarctica, on the other hand, is a continent. P

It is a huge, ice-covered island surrounded by oceans. P

Antarctica is also colder than the Arctic. P

There are two reasons for this. P

First of all, Antarctica is much higher and has many tall mountains. P

The higher the land, the lower the temperature. P

Also, the water of the Arctic Ocean is warmer than the ice above it. P

It keeps the Arctic's temperature from dropping too low. P

Another difference is the people that live there. P

Many native people have been living in the Arctic for thousands of years. P

However, Antarctica has never had any native people. P

Only some scientists and researchers live there today. P

Finally, there are very few plants and animals in Antarctica. P

There are no land mammals. P

There are only birds, including millions of penguins. P

There aren't any penguins in the Arctic, but many land animals live there, including reindeer and foxes. P

The best-known Arctic land animal is the polar bear. P

Lesson 8-34

We were full of excitement when we set sail in August 1914. P

There were 27 of us plus "the Boss," Ernest Shackleton, all eager to explore Antarctica. P

But trouble came on our way there. P

In January 1915, our ship, the Endurance, became trapped in the ice. P

Eventually, the moving ice began to crush the ship. P

In October, we had to abandon the Endurance. P

We took our food and lifeboats and camped on the frozen ocean. P

When it melted enough, we sailed for land. P

In mid-April 1916, we reached Elephant Island, a freezing, deserted place where no ships traveled. P

To get help, the Boss decided to go to South Georgia Island, 1,300 kilometers away. P

There, he knew he could find sailors hunting whales. P

About a week later, he took five of us with him in one of the lifeboats. P

For over two weeks, we thought the stormy waves would sink us, but we finally landed on South Georgia in May. P

However, the sailors lived on the other side of the island's mountains. P

We risked freezing to death as we climbed for 36 hours. P

Finally, we found help. On August 30, 1916, we returned to Elephant Island. P

Our crewmates were there on the beach! "Are you all well?" shouted the Boss. P

"All safe, all well," one of them answered. P

It was the happiest moment of our lives! P

Soon, everyone was safely aboard the ship, ready to go home. P

Lesson 8-35

Some people might think paintings should show something special. P

For them, paintings of soup cans wouldn't be "art. P

"But for an artist named Andy Warhol, they were. P

He found his own way to make art that showed ordinary things. P

Warhol's interest in art developed early in his life. P

He was very sick as a child, so he spent a lot of time in bed drawing pictures. P

He had a lot of talent and decided to study art at college. P

As a young adult, Warhol began a career as a commercial artist. P

He made advertisements for magazines. P

Later, Warhol began to exhibit paintings in art galleries. P

However, he didn't paint special or unusual things. P

He painted what people saw every day like Campbell's soup cans and Coca-Cola bottles. P

He also painted famous people such as Marilyn Monroe. P

For him, these familiar images were just as important as traditional art. P

Warhol also started his own art studio called "The Factory." P

Here, teams of people made copies of his paintings. P

Each copy looked the same. P

Now his art was mass-produced, just like a soup can or soda bottle. P

Many people paid attention to Warhol's work. P

It had a strong effect on what they called "art. P

"Now many people see beauty in ordinary or even mass-produced things. P

Art is all-around us, even at the grocery store. P

Lesson 8-36

There once was an artist. He painted portraits for a living. P

He earned a great deal of money and was very famous. P

The secret of his success was simple. P

He didn't paint people as they really looked. P

He painted them as they wanted to look. P

For the old men, he painted pictures that made them look a little younger. P

For the fat women, he painted ones that made them look a little thinner. P

People were always pleased with their paintings, and the painter always had a lot of customers. P

One day, an unusual customer visited the painter's studio. P

He was the ugliest man the painter had ever seen. P

His face was covered in dark hair, and he had tiny eyes and horrible, long teeth. P

Amazingly, this ugly man wanted a portrait of himself. P

He paid his money and sat down. An hour later, the portrait was done. P

The artist nervously turned it around for the customer to see. P

Within seconds, the man became upset because the portrait looked nothing like him. P

He demanded his money back. Just then, the artist's cleaning lady came in. P

She looked at the portrait and said how handsome the man looked in it. P

Suddenly, the customer looked much happier. P

"Yes, thank you," he said with a smile. P

"It's a perfect likeness. "Then, he took his painting under his arm and left. P

Lesson 8-37

Spider webs are amazing. They are very complex, so spiders build them in several steps. P

The spider starts with the most important part: the first thread. P

The spider fastens one end of the thread to something solid and then releases it into the wind. P

With some luck, the other end catches on another object. P

Then, the spider makes the thread stronger with more threads. P

Next, the spider makes another thread beneath the first one and attaches it to the same two places. P

Because it is loose, it makes a V-shape. P

The spider then adds a new thread to the bottom of the V-shape, changing it into a Y-shape. P

After it makes edges around the Y, it adds many straight threads from the center of the Y to them. P

That way, it can cross from one side to another. P

The spider then creates a spiral of threads from the web's center to its edges. P

These are not sticky, so the spider can easily walk around on them. P

After that, it replaces the non-sticky spiral with a sticky spiral that can catch insects. P

It starts on the edges of the web and moves toward the center. P

Finally, the web is finished. The spider sits in the center and waits for insects. P

Eventually, the web will become less sticky. P

When that happens, the spider must weave a new one. P

Lesson 8-38

Turtle and Spider were friends. P

One day, Turtle happened to visit Spider at dinnertime. P

It was polite to serve a visitor at mealtime, but Spider was greedy. P

He didn't want to share his food. P

Spider told Turtle that in his country, it was rude to eat with dirty feet. P

Then, he sent Turtle to the stream to wash his feet. P

Turtle came back a few minutes later. P

To his surprise, half the meal had already been eaten. P

To make matters worse, his feet were dirty again from the muddy path! P

Spider told him to go and wash them again. P

This time, Turtle walked on the grass to keep his feet clean. P

Unfortunately, when he got back, the meal was all finished. Turtle was angry. P

He decided to pay Spider back for what Spider had done to him. P

The next month, Turtle politely invited Spider for dinner. P

Turtle's home was underwater at the bottom of a river. P

However, Spider's arms and legs were too light, so he couldn't sink under the water. P

Cleverly, he filled his coat pockets with rocks to make himself heavier. P

He quickly sank to the bottom and happily sat down to eat. P

Then, Turtle said that in his country, it was rude to wear your coat at the dinner table. P

Spider took off the coat, but this made him float back to the surface. P

He didn't eat a single bite! Without his jacket, he couldn't stay for dinner. P

Lesson 8-39

A baseball player swings his bat and hits the ball. P

How far will it go? Will it be a home run? P

That depends on many different things, but one of them is air density. P

What is air density? Air is made up of tiny particles. P

When these particles are close together, the air has a higher density. P

When they are far apart, the air has a lower density. P

As a baseball moves through the air, it hits these particles like a person trying to walk through a crowded room. P

This is called air resistance, and it slows the ball down. P

So when the air density is high, the ball doesn't travel as far. P

In high places, the air has a lower density. P

Higher temperatures also make the air less dense. P

Lower air density means the air particles are more spread out. P

When flying through them, the baseball encounters less air resistance, allowing it to travel farther. P

That's why there are generally more home runs at baseball stadiums in high areas and on hot days. P

High humidity also makes the air have a slightly lower density. P

Humidity is the amount of water in the air. P

However, baseballs don't actually travel farther on humid days. P

This is because the water makes the ball heavier, which slows it down. P

Lesson 8-40

The boys on the St. Andrew's soccer team were excited. P

They were going to play the first game of the season against their rivals, St. David's. P

But right from the beginning, things started to go wrong. P

First, they didn't leave ontime. Before they left, the coach counted everyone on the bus. P

Their goal keeper was missing. P

Eventually, he showed up, but they were already 25 minutes late. P

At the game, they had to play without warming up enough. P

Usually, they stretched before the game. They also did some running exercises with the ball. P

But that day, they arrived too late. P

There was only enough time to change into their uniforms. P

Then, they had to start playing right away. During the game, something was clearly wrong. P

No one ran fast enough to keep up with the St. David's players. P

A few players also got terrible pains in their legs. P

The coach knew why. They hadn't warmed up. P

There was nothing the team could do about it. P

St. David's controlled the ball, and they took lots of shots at the goal. P

In the end, St. Andrew's lost five to nothing. P

On the bus after the game, the coach had a long talk with everyone. P

He said it was crucial to be on time. P

And he looked right at the goal keeper when he said it. P

Lesson 8-41

We all live in communities. P

There are many different kinds of communities in the world - families, schools, neighborhoods, clubs and cities. P

This shows that we can be a member of many communities at the same time. P

A community is a place where people live, work and play together. P

People share things and help each other in the community. P

People need some things to live, for example, food, clothing and a home. P

Can you obtain all these things by yourself? Maybe it is hard. P

If you are not alone and belong to a community, the people in the community will help you get them. P

This is why people live in communities. P

Nowadays, a new kind of community has appeared. It's the online community. P

The development of the Internet made online communities possible. P

You can meet others, make new friends, and share information in an online space. P

Lesson 8-42

Mother's Day is a day to honor mothers. P

On this day, children give cards, gifts and flowers to their mothers. P

Mother's Day is celebrated on different days around the world. P

In the United Kingdom, it is in March. P

It was called Mothering Sunday before. P

In the 1700s, there used to be child servants working in rich people's houses. P

On Mothering Sunday, they could go home and make a special fruit cake for their mothers. P

In the United States, Mother's Day falls on the second Sunday of May. P

A woman named Anna Jarvis worked hard to make Mother's Day a holiday. P

Making a special day for mothers was her mother's wish. P

Anna succeeded in 1914, when Mother's Day became a national holiday. P

What is the best Mother's Day gift? P

First of all, you have to appreciate everything that your mother has done for you. P

Hug your mother and say, "Thank you, Mom!" P

Lesson 8-43

You can easily find plastic bottles anywhere. P

Plastic is commonly used because it is light and strong. P

But many used plastic bottles are buried in landfills. P

Do you know how long it takes for a plastic bottle to decay? P

It takes 1,000 years! For this reason, most communities try to recycle them. P

Here are a few tips on recycling plastic bottles. P

First, wash them out with water. P

You don't need to use dish soap. P

This is just to remove any remaining liquid. P

Second, take the caps off the bottles. P

Caps are made from a different kind of plastic. P

They can't be recycled with the bottles. P

And third, step on the bottles to make them flat. P

This way, recycling trucks can carry more bottles at once. P

Follow these tips, and you will become a better recycler. But don't stop there. P

Find out how to properly recycle glass, cans and paper, too! P

Lesson 8-44

In Ethan's home, everyone does chores. P

Ethan does the dishes and keeps his room clean. P

His dad takes out the garbage and washes the car. P

Ethan often complains about doing chores. So does his dad. P

One Sunday, Ethan's mom didn't get out of bed. P

"I'm very sick," she said weakly. P

"Could you two do all of the housework? Just for today?" she asked. P

"Sure. No problem," said Ethan and his dad. But it was not easy. P

They had to clean the house, make lunch, do the laundry, and iron clothes instead of Ethan's mom. P

The chores were endless! By evening, Ethan and his dad were tired. P

"Mom, I didn't know you did so much work! From now on, I'll do more chores," said Ethan. P

Ethan's dad nodded along. Ethan's mom smiled and said, "Hmm. P

It's a miracle! Suddenly, I'm all well!" She got up and made dinner with her son and husband. P

Lesson 8-45

If you travel to Australia, you will probably see two unique Australian animals - koalas and kangaroos. P

They are very popular all over the world. P

Kangaroos have strong hind legs with long feet. P

They can hop on their hind legs. P

Kangaroos live in groups of ten or more. P

They manly eat grass and leaves. P

Koalas have strong thumbs that help them climb trees. P

They live in eucalyptus trees and eat only their leaves. P

Koalas live alone and sleep 18 to 20 hours a day. P

Kangaroos and koalas have something special in common: both females have pouches. P

As soon as their babies, called "joeys," are born, they crawl into their mothers' pouches. P

The newborn babies are only two centimeters long. P

They drink their mothers' milk and grow there for months. P

One thing is a little different, though. P

A kangaroo's pouch opens upwards, but a koala's pouch opens towards their hind legs. P

Lesson 8-46

There is a big tree. A little boy comes to the tree every day. P

He likes to climb it. He often picks and eats the tree's fruit. P

He sometimes sleeps in its cool shade. P

Trees are very important to both people and animals. P

Some animals make their nests in trees. P

People and animals eat fruits and seeds from trees. P

Trees provide cool shade for them. P

Also, trees produce oxygen and help keep air clean. P

People breathe in oxygen and breathe out carbon dioxide. P

On the other hand, trees take in carbon dioxide from the air and give out oxygen. P

Trees are helpful to people in other ways, too. P

Wood is a good material for building houses and making furniture or paper. P

It can be also used as fuel. But many trees are cut down each year. P

Do you worry about this? Then let's plant trees together on Arbor Day! P

Lesson 8-47

Chameleons are famous for changing colors. P

Mostly they are green or brown, but they can change into various colors. P

If you watch a chameleon at the right time, you can actually see it change colors. P

Many people think that a chameleon changes colors to match its surroundings, but there are other reasons. P

Sometimes, it has to do with light. P

How does a brown chameleon change in the sun? P

It turns green because a lighter color reflects more sunlight. P

Sometimes, it has to do with temperature. P

How does a cold chameleon change? It turns a darker color to take in more heat. P

A chameleon's mood is very important to color change. P

Is a chameleon turning red and yellow? Then you had better watch out. It is angry! P

Is a chameleon showing bright colors? P

Then say "Go, chameleon!" It is trying to find a mate! P

Lesson 8-48

Day 1 Today I started to grow some kidney bean plants. P

I put three beans on some cotton in a plastic dish. P

I poured water on the cotton and made it soggy. P

Day 3 My little kidney beans are bigger. P

They were dark red at first; now they are light pink. P

One of them has started to sprout. P

The sprout is white and looks like a tail. It's very fascinating. P

Day 5 All three beans have sprouted. P

I planted the sprouted beans in a small pot. I covered them with soil. P

Then I put the pot by the window in the sunshine. P

Let's meet again in a few days. P

Day 10 I am worried about my kidney beans. P

I watered them every other day, but they won't spring up. P

Are you okay in there, little beans? I can't wait to see you. P

Day 12 I noticed something green in the pot. P

At last, the very young plants have come out of the soil. P

They were seed leaves. Good to see you again, little beans! P

Lesson 8-49

Water covers about 70% of the earth's surface. P

The salty oceans hold 97% of this water. P

The remaining 3% is fresh water. P

But most of that is in the form of ice at the poles. P

Only 1% of all the water on the earth is available for us to drink. P

This fresh water is found in rivers, lakes and groundwater. P

The earth's water moves in a cycle. P

It moves from the oceans to the air and to the land, then back to the oceans. P

This is called the water cycle. P

The sun heats up water on the earth and turns it into vapor. P

The water vapor rises into the air. P

As the air cools, this vapor forms clouds. P

The clouds get heavy and water falls to the earth's surface as rain or snow. P

It flows into lakes and rivers. P

The lakes and rivers take it back to the sea. P

The cycle begins over and over again. P

Lesson 8-50

Take a look outside. What's the weather like today? P

That may be a simple question to answer. P

Then, what is the weather usually like throughout the year? P

Climate is a place's usual weather throughout the year. P

It shows how hot or cold the temperature is. P

It also shows how much rain or snow falls in that place. P

Different places in the world have different climates. P

A particular place's climate is most influenced by its location on the earth. P

Sunlight hits the earth most directly at the equator. P

Therefore, places near the equator are much warmer than places near the poles. P

Other influences on climate include the oceans, wind and mountains. P

Meanwhile, climate affects an area's vegetation; that is, its plant life. P

Some plants need lots of sun and water to grow. Other plants need less. P

Fruits like pineapples and bananas grow well in hot climates. P

Grains like corn and wheat, however, do just fine in cooler climates. P

Lesson 8-51

We use electricity every minute of every day. P

Can you name all the things that need electricity at home? P

There are lights, computers, TV sets, refrigerators and washing machines. P

Maybe you can name more things. P

Electricity is energy. We make electricity using energy sources. P

Energy sources are divided into two forms: renewable and nonrenewable. P

Renewable energy is made from the sun, water and wind. It can never be used up. P

But non-renewable energy can only be used once and cannot be replaced. P

We can obtain this energy from oil, coal and natural gas. P

These are called fossil fuels because they formed over millions of years. P

More people use renewable energy nowadays. P

Some people use solar energy to heat their homes. P

Some cars run on fuel from corn or soybeans. P

Future cars might run on corn juice, not oil or natural gas! P

Lesson 8-52

"Wait," said Bill. "These curved lines mean a stream. Is there a stream nearby?" P

"No," said Julie. "And that's a railroad symbol behind the stream. P

There's no railroad around here, either." P

Suddenly, an image flashed across Julie's mind. P

She grabbed Bill's hand and led him back to their classroom. P

She pointed to a picture of their school on the wall. P

It looked just like the map! They looked at the back of the picture. P

Behind the playground on it, they found a golden chocolate bar! P

At lunch time, Mr.Hill gave treasure maps to all his students and said, P

"Go to the X and you will find a treat!" P

Bill and Julie studied their maps. P

"This S symbol stands for school. And these are fence symbols," said Bill. P

"Right," said Julie. "And this swing stands for a playground. The X is here!" P

Bill and Julie rushed out to the playground. P

But they found nothing there. P

Lesson 8-53

On January 27th, 1756, a musical genius was born in Salzburg, Austria. P

His name was Wolfgang Amadeus Mozart. P

Mozart played the harpsichord when he was just three years old. P

He could hear music once and play it right back. P

At age four, he began to compose his own works and he composed his first symphony at age eight! P

He could even compose music in his head. P

Mozart went to Munich and Vienna on his first musical tour when he was six. P

He spent much of his youth touring Europe. P

During his trips, Mozart composed many works. P

Mozart died in Vienna in 1791. He was only 35 years old. P

Mozart left over 600 works. P

He wrote almost every kind of music from symphonies and operas to popular music like dances. P

His most famous operas include The Marriage of Figaro, Don Giovanni and The Magic Flute. P

More than 200 years after Mozart's death, his music is still well-loved. P

Lesson 8-54

There are men and women by the seaside. When the gun goes off, they sprint to the water and swim. P

As they finish swimming, they sprint to their bikes. P

After biking, they change into running shoes. P

This is a triathlon race. A triathlon is an endurance sport. P

It consists of three different stages swimming, cycling and running. P

The race is continuous, with no stops between the three stages. P

The most famous triathlon event is the Ironman Triathlon in Hawaii. P

In this race, participants must swim 3.8 kilometers, cycle 180 kilometers, and then run 42.2 kilometers. P

If you get through the race within 17 hours, you can be an "Ironman." P

It's very hard to train for a triathlon because you have to cover three different sports. P

Each sport makes use of different muscles in your body, so you need to exercise to strengthen all your major muscles. P

Lesson 8-55

Dressed-up performers sit on stage. They begin to play classical music. P

The audience quietly listens. P

Classical concerts are more formal than other concerts. P

Are you worried about how to act at a classical concert? P

Here is a guide to good concert manners. P

Be on time. You will not be allowed inside after the performance starts. P

Sit quietly. People want to listen and fall into the music. P

Performers need to focus on their music. P

Don't do anything to distract the performers. P

Don't talk or make any loud noises. P

No eating or taking pictures, either! P

Applaud at the end of the entire piece. P

You may be confused about when to clap. P

In other kinds of music, the audience claps whenever the music stops. P

But in classical music, one piece may have several parts, each with its own ending. P

Clapping after each part is not good manners. P

Lesson 8-56

Tommy, Jim and Matt are players on a soccer team. P

Tommy is the goalie, Jim is a midfielder, and Matt is a striker. P

Matt stood out among the strikers. Their team won game after game. P

After every game, Matt showed off a lot. P

"Did you see my goal?" "I'm the best striker!" Tommy and Jim said nothing. P

'They must be jealous,' thought Matt. P

One day, Tommy and Jim missed a game because they were both sick. P

Matt tried several times to make a goal, but he couldn't. P

The opponent team made three goals. P

He thought, 'Jim always passed me the ball. P

And Tommy always blocked the other team's shots. P

'The next day, Matt met Tommy and Jim. P

"I'm sorry for bragging, you guys. P

I'm not great by myself. We are a team of great players," he said. P

"But you're the greatest, right?" said Tommy. P

"Well … yeah," said Matt. They all laughed. P

Lesson 8-57

Here is a riddle: If there isn't anything, this number appears. P

If there is something, it doesn't appear. P

What is this magic number? The answer is zero. P

Zero is used as a symbol for nothing. Zero is a very strange number. P

If you add zero to or subtract zero from any number, that number stays the same. P

If you multiply any number by zero, you get zero. P

You cannot divide a number by zero. P

Zero is also a great number. Here is the number 1. Let's write 0 right behind 1. P

What number is made? Of course, it is 10. P

If you write two 0's or three 0's, it becomes 100 or 1,000. P

Thanks to zero, you can easily express not only millions and billions but also boundlessly large numbers. P

If the ancient people hadn't invented the symbol "0" for zero, what symbol would we be using now? P

Lesson 8-58

You need to measure the length of something. P

You probably look for a ruler or a measuring tape. P

But you can't find one. What do you do? P

Why don't you use your hand or arm? P

Before measuring tools* were invented, people used their body parts to measure. P

One popular unit was the cubit. P

A cubit is the length from your elbow to the tip of your middle finger. P

A person's cubit is usually around 43~56 centimeters. P

The pyramids of Egypt were built in cubits. So was Noah's Ark! P

Other body parts such as palms and feet were used to measure, too. P

The unit foot was based on the length of a man's foot! P

Farmers walked around and measured their land with their feet. P

Using body parts to measure was easy, but everyone's cubits, palms and feet were different lengths. P

And so, standard units of measurement were developed. P

Lesson 8-59

What is your favorite shape? Is it a square, a circle or a triangle? P

All shapes are special, but one is known to be perfect. P

That is the circle. Let's put a dot in the center of a circle. P

Now draw a line that connects two opposite points on the circle and passes through the dot. P

This line is called a diameter. You can fold a circle along any of its diameters. P

Its two halves are exactly the same. A circle is symmetrical all around. P

Because of its symmetry, the circle is considered to be the perfect shape. P

Look around and you can see many circular things: cups and plates, manholes, coins, and so on. P

Why are manholes round? Other shapes have edges, but a circle does not. P

So, you can put a manhole cover in any direction and it still fits the hole. P

Other shapes could get stuck in the hole. P

Lesson 8-60

Brian, in the fifth grade, enjoys math. P

Right now, he is learning to divide fractions. P

His teacher says, "Keep in mind KFC." P

"Kentucky Fried Chicken?" asks a student. P

"Yes, but also Keep the first fraction, Flip the last fraction, and Change the sign to multiply. P

One-third divided by one-sixth? Turn it into one-third times six!" "Ah!" says the class. P

Every year, Brian's school has a math contest. P

This year, Brian takes part in the contest and becomes one of the last two competitors. P

"We will now have a speed quiz," says the host teacher. P

Brian and his opponent both answer the first two questions correctly. P

"Now the last question: what is three-fourths divided by one-twelfth?" The other student frowns. P

But Brian quickly thinks, "KFC. P

Three-fourths and twelve, multiplied. P

"Brian's hand shoots up."Nine!" he says. P

Brian is the math champion! P

The next day, Brian brings nine buckets of KFC chicken for his classmates. P

Lesson 8-61

People are throwing tomatoes at one another. P

It looks like a fight, but everyone is laughing. What is going on? P

You can see this exciting scene during La Tomatina, a tomato fight festival in Bunol, Spain. P

This festival is held every year on the last Wednesday of August. P

Back in the 1940s, some friends got in a fight on the streets. P

They took fruit from a nearby food stand and threw it at one another. P

Passers-by joined in their fight. P

Everyone had so much fun that it became a yearly festival. P

On the morning of the festival, people begin to gather at the town's main plaza. P

At 11 o'clock, tons of tomatoes arrive and are poured out onto the crowd. P

Tomatoes start flying everywhere and soon everything is covered in red tomato juice. P

People shout and have great fun. P

Two hours later, the fight ends and everyone helps to clean up. P

In a few hours, the streets are clean again. until next year! P

Lesson 8-62

We usually use a fork or chopsticks to pick up food. P

How were these two eating utensils developed? P

Forks are rooted in Western culture. P

In the West, people raised cows and sheep. P

Naturally, they lived on meat. P

They would cut the meat with a knife, then just eat it. P

Ancient Greeks first used a fork with two points to hold the meat while cutting. P

This was later developed into forks for eating at the table. P

More points were added to pick up smaller bits of food. P

Chopsticks are a part of Eastern culture. P

In the East, people raised mostly crops and ate grains and vegetables. P

Food was boiled or steamed in large pots. P

Two tree branches were used to turn the food while cooking. P

The first chopsticks were used by the Chinese 5,000 years ago. P

The Chinese learned that smaller bits of food cooked quicker. P

Chopsticks were developed to pick up these food bits. P

Others soon began eating with chopsticks, too P

Lesson 8-63

In 2007, a quiet, chubby man appeared on a British talent show. P

"I am here to sing opera," he said nervously to the judges. P

Sing opera? The judges looked very doubtful. P

Then his sweet voice rang out in a beautiful aria. P

The judges and the crowd were stunned. P

This is the true story of Paul Potts. P

Paul loved to sing from childhood and wanted to be an opera singer. P

But he became a salesman. He wasn't happy with his job. P

Instead of being a professional singer, he kept singing in an amateur opera group. P

But in 2003, he had health problems and underwent surgery. P

He also had a terrible bike accident and could neither work nor sing for many months. P

He entered the talent show to give his singing dream one last chance. P

One of the judges called Paul "a little lump of coal that is going to turn into a diamond. P

"And that is what he did. Paul is now an international star. P

If you work hard enough, your dreams can come true. P

So never give up on your dreams! P

Lesson 8-64

On a spring day, the Sahids received a party invitation. It said 'BYO food' on it. P

"That means Bring Your Own food," explained Mrs. Sahid to her daughter Alka. P

"Each guest takes a dish to share. This is called a potluck party." P

Mrs. Sahid and Alka decided to make chappatis for the party. P

Mrs. Sahid made dough out of flour, water and salt. P

Alka helped her make little balls of dough. P

They flattened the dough and baked it in a hot pan. P

Then they piled up the chappatis in a basket. P

The Sahids arrived at the party. P

Many neighbors were already there with their food. P

The Sahids tried many different dishes. P

Mrs. Sahid also offered chappatis to her neighbors. P

She explained, "These are chappatis, a common Indian food." P

The neighbors tried it and loved it. P

Sharing food made Alka feel much closer to her neighbors. P

On the way home, Alka said to her mom, P

"It was a great party! I can't wait till the next potluck party. P

Lesson 8-65

Seeds are great travelers. They can travel far away from their homes. P

There are different ways that seeds travel. Some seeds travel by wind. P

These seeds are usually light or wing-shaped. P

Dandelion seeds have light, fine hairs that catch the wind. P

Maple seeds have flat wings that twirl in the wind. P

Seeds like coconut seeds travel by water. P

Coconut seeds are covered in a thick layer of fiber. P

The fiber allows the coconut seeds to float on water. P

Some seeds are carried away by animals. P

Some like mistletoe seeds are very sticky. P

Others have sharp hooks. These seeds cling to animal fur. P

They will later drop off at a distant place. P

Humans can carry seeds on their clothes and shoes, too. P

Also, when animals eat fruit, the fruit seeds come out later in their droppings. P

Some plants don't wait for the seeds to fall off. They spit them out instead! P

The fruit of a squirting cucumber will open up and spit seeds out into the air. P

Lesson 8-66

Look at the frog sitting by a pond. P

It underwent many changes to become a full-grown frog. P

Egg: A female frog lays a mass of eggs in the water. P

The eggs are usually covered with a jelly-like material which holds them together. P

Tadpole: Soon, a tadpole hatches from one of the eggs. P

At this point, the tadpole consists of gills, a mouth, and a tail, so it is similar to a little fish. P

It breathes with its gills. It doesn't have any legs. P

It swims around with its long tail. P

Tadpole with Legs: The tadpole starts to change. P

The two hind legs first grow, and then the front legs pop out. P

It begins to eat insects and plants. P

Froglet: A froglet looks like a small adult frog. P

Its tail keeps shrinking. It loses its gills and breathes with lungs. P

It will leave the water soon. P

Adult Frog: The tail is completely gone. P

It will now live on dry land and in water. P

When it meets its mate and has eggs, the whole cycle will begin once again. P

Lesson 8-67

Trees and tall plants block out the sun. The land is covered in water. P

There are things moving underwater. P

Sounds creepy? Most swamps are like this. P

Swamps are low lands that are underwater for most of the year. P

The water comes from nearby lakes, rivers and streams. P

Swamps may not be everybody's favorite place, but they are very important. P

For one thing, swamps prevent flooding. P

In a storm, swamps absorb water like a sponge. P

They release the water again in dry weather. P

Swamps are also important to migrating birds like ducks, geese and swans. P

Swamps provide a resting place for them during their long journey. P

Swamps are also home to various animals. P

Animals like crayfish and shrimp live in the water. P

Crocodiles and beavers live at the surface of the water. P

Birds and insects live above the water. P

And raccoons and snakes live on the spongy land near swamps. P

Lesson 8-68

Emily was excited. It was the day of her submarine trip. P

She would travel thousands of meters below the sea. P

It was pitch-black underneath the water. P

Suddenly there was a flash of light. P

It was coming from a strange-looking fish. P

It had an enormous mouth and a very long tail. P

"That is a gulper eel," said the captain. P

"The tip of its tail lights up to attract prey. P

Its jaws are loose so its mouth can open wide. P

It can eat prey much larger than itself. P

Its stomach stretches, too. So it just swallows its prey in one gulp." P

Just then, Emily saw the gulper eel turn its way. P

"Can it eat something as big as this submarine?" asked Emily. P

"No," said the captain. But the gulper eel was now coming towards them. P

"Hurry! Let's get away!" cried Emily and closed her eyes. P

After a few seconds, she opened her eyes. P

The gulper eel had eaten a nearby fish. P

Embarrassed, she smiled weakly at the captain. P

Lesson 8-69

Take a soda can and shake it well. P

What happens next? Soda bubbles build up inside. P

When you open it, the soda spills out and makes a mess. P

It looks like an erupting volcano. P

How do volcanoes form? Underneath the earth's surface flows hot liquid rock called magma. P

There are also lots of gases, steam and dust. P

These sometimes build up and burst out of the earth's surface. P

Hot liquid called lava and sand-like rock spill out. P

These harden and become volcanoes. P

When volcanoes erupt, they can cause a lot of damage. P

Earthquakes often occur before and after volcanoes erupt. P

Hot lava flows over land and destroys it. P

Plants and animals that lived on the land die, too. P

Harmful gases also burst out into the air. P

Volcanoes, though, can be useful in some ways. P

Volcanic heat can be used to run a power plant. P

We can also use the various minerals melted in the lava. P

Volcanic sites are good for sightseeing and can create wonderful spas. P

Lesson 8-70

A polar bear at the zoo is hugging a big chunk of ice. P

He dreams about floating on an iceberg and hunting for seals. P

Polar bears live on icebergs in the Arctic. P

How did icebergs first form? Thousands of years ago, snow piled up on land near the poles. P

The snow froze into layers of ice. These are called glaciers. P

Due to water movements, wind and temperature, parts of glaciers near the sea melt and break free. P

These are icebergs. Icebergs are made of fresh water that is not salty. P

They appear white because they are full of air bubbles. P

They float thousands of kilometers down the sea until they melt away. P

Because the world's temperature keeps going up, more and more icebergs are breaking free. P

And these icebergs are melting too quickly. P

This means animals such as polar bears and seals are losing their habitats. P

Scientists say that they could be extinct in the near future. P

We must work to protect these familiar animals. P

Lesson 8-71

On a clear sunny day, look up, and you can see the blue sky. P

Why is the sky blue? Why is it not yellow or green? P

It has to do with light from the sun and the earth's atmosphere. P

Light from the sun looks white, but is actually made up of all colors of the rainbow. P

When sunlight passes through the air, the light bumps into gas molecules and dust in the air. P

When the light hits a gas molecule, it gets scattered in different directions. P

Some colors of light, like red and orange, pass straight through the air. P

But blue light bounces off in all directions: forward, sideways, and backwards. P

This blue light eventually reaches your eyes from all over the sky. P

This makes the sky look blue. P

How about in space? In space, there is no air. P

This means that there is nothing for light to bounce off. P

The light just passes through. P

As none of the light gets scattered, the sky looks black. P

Lesson 8-72

Jason's dad took him along on a trip to Dubai. P

As the plane flew lower, Jason saw something on the southern coast. P

It looked like a huge sand drawing. P

"What is that, Dad?" asked Jason. P

"That's Palm Jumeirah. It's an island built by people. P

See how it is shaped like a palm tree?" said Dad. P

"Yes, I see!" cried Jason with excitement. P

The airport was very busy. Jason felt more excited. P

He couldn't wait to look around the city. P

They got in a taxi and headed towards the coast. P

Jason saw skyscrapers everywhere. P

They were the tallest buildings he had ever seen. P

"Dubai used to be a small fishing village fifty years ago," explained the driver. P

Now look at it. P

We've turned this desert area into one of the most popular tourist cities in the world. P

Jason pointed up ahead and cried, P

Look, Dad. Palm Jumeirah! It's even more amazing up close. P

The driver proudly smiled and said, "Welcome to Dubai, little one." P

Lesson 8-73

A long time ago, people often exchanged goods. P

Let's say one man had a lot of potatoes and another had a lot of peas. P

If they both wanted the other's goods, a trade would take place. P

This kind of trade is called bartering. P

But there was a problem with bartering: it was hard to carry around goods to trade. P

Besides, the goods went bad easily. P

So people began to use cowry shells to purchase goods, instead. P

Cowry shells were widely used as money throughout history. P

Around 1000 B.C, the Chinese made metal money shaped like cowries, knives and spades. P

This early metal money developed into round coins. P

Ancient Chinese coins were made of base metals. P

They had holes so they could be put together on a chain. P

Outside of China, the first coins were created in Lydia - modern western Turkey - around 700 B.C. P

These were made of precious metals such as gold, silver and bronze. P

Gradually, coins became common all over the world. P

Lesson 8-74

On a store shelf, there is a big bar of milk chocolate. P

Have you ever wondered how it got there? P

Chocolate is made from the seeds of cacao trees. P

Cacao trees only grow in warm places near the equator. P

Farmers pick cacao pods and take out the seeds inside of them. P

They ferment the seeds then dry them in the sun. These are now cacao beans. P

They send the beans to chocolate factories around the world. P

At the factory, cacao beans are first roasted. This brings out their flavor. P

Then a machine separates the meat from the shell. P

The meat part is ground into liquid chocolate. P

This pure chocolate is very bitter! P

Sugar and milk are mixed with the chocolate for days. P

Then it's heated and cooled many times to make it smooth. P

Now it's ready to be poured into molds and hardened into chocolate bars. P

When the chocolate is hardened, it's wrapped and sent to stores. P

And so, that is how that chocolate bar came to be there. P

Lesson 8-75

Once there were several trade routes. P

They stretched thousands of kilometers from China to the Mediterranean Sea. P

At first, people traveled across them to trade silk. P

Together, they were called the Silk Road. P

The Silk Road began around the second century in China. P

People rode wagons and sold silk all across the land. P

They traveled farther and farther. P

Soon, they traded across China, Central Asia, India, Africa and all the way to Rome. P

The Silk Road brought together the East and the West. P

As it developed, other goods besides silk were traded. P

Silk, fur and ceramic goods traveled from east to west. P

Ivory, precious stones and spices traveled from west to east. P

As people traveled back and forth, they picked up one another's cultures. P

China's four greatest inventions - papermaking, gunpowder, the compass and printing were all introduced along the Silk Road. P

Buddhism also spread from India to China. P

The Silk Road acted as an important cultural bridge for many centuries. P

Lesson 8-76

One day, Brad's dad brought home a big piggy bank. P

"Let's put our change in here," he said. P

Every night, Brad's parents put their coins in the piggy bank. P

Brad began to follow their lead. P

Soon, the big piggy bank was full. P

Brad wanted to spend the money. P

But his dad proposed, "How about putting it in the bank for a while?" P

Brad agreed, so they put their money in a bank account. P

Brad's family kept saving and their account grew bigger. P

Around Christmas, Brad and his dad went to the bank and checked their account. P

There was some extra money in it! P

Brad's dad said, "That's called interest. Interest is money paid to savers by the bank. P

Now how do you want to spend our money?" P

Brad answered, "Well, I'll think about it." P

At that very moment a bell rang. P

Brad turned around to the sound of the bell and saw a charity kettle. P

"Dad, I want to spend our money meaningfully. P

I'd like to put it in that charity kettle. Is that okay?" P

His dad hugged Brad and said, "That sounds wonderful. P

Lesson 8-77

Do you like donuts or pizza? Be careful - they might have trans fats in them! P

What are trans fats? Trans fats are artificial fats. P

They are created in the process that adds hydrogen to liquid vegetable oils to make them more solid. P

Trans fats can be found in many foods - especially in fast food. P

Many food companies and restaurants like to use trans fats P

because they're easy and inexpensive to use, and they last for a long time. P

They usually use margarine and shortening when they make fried foods like French fries and donuts. P

But trans fats are bad for your health. P

Trans fats are often called 'the silent killer'. P

They slowly build up in your blood and around your stomach. P

In addition, they make other fats stay in your body. P

Eating trans fats increases your risk of developing heart diseases and diabetes. P

To keep your health, stay away from trans fats. P

Before choosing foods, first read the nutrition facts on food labels and make sure that your food does not contain them. P

Lesson 8-78

A caterpillar will go inside a cocoon. P

After a period of change, it will turn into a beautiful butterfly. P

Whether you are a boy or a girl, you will also go through a period of change. P

This period is called puberty. Puberty starts at a different age for everyone. P

It can start as early as age 8, or as late as age 15. P

When you go into puberty, a part of your brain sends out hormones. P

These hormones will make your body develop in many ways. P

Your arms, legs and feet will grow quickly. P

If you are a boy, your shoulders will grow wider. P

Your voice will crack then grow deeper. P

If you are a girl, your body will become curvier. P

During puberty, you may feel angry and confused. This is very normal. P

Your mind and your body are just adjusting to the changes. P

Try to think of puberty as an adventure. P

Waiting at the end is a new you. P

Lesson 8-79

There is a picture of a pyramid with colorful vertical lines. P

There is a stairway on its left. A figure is running up the stairs. P

What does this symbol mean? This is a food pyramid. P

To stay healthy, we must eat a balanced diet. P

There are five main food groups. P

The vertical lines represent each one. P

Orange is for grains like rice and bread. P

Green is for vegetables, and red is for fruits. P

Blue is for milk, yogurt and other dairy products. P

Purple is for meat, fish and nuts. P

And yellow is for fats and oils - we need a little of them in our diet, too. P

Some lines are thicker than the others. P

We should eat more foods from those groups. P

As for the running figure, it means that exercise is important, too. P

We should eat well, but we should also get plenty of exercise. P

Doing both is not always a piece of cake. P

But like the figure, take it one step at a time. P

Lesson 8-80

One day, Jessica's classmate Amanda started wearing glasses. P

Jessica thought Amanda looked cool. P

That night, Jessica took her mom's glasses. P

She went to the mirror and tried them on. P

"What are you doing?" asked her mom. P

"Do you need glasses?" "Uh… maybe," she lied. P

She wanted to be like Amanda. P

The next day, Jessica went to the eye doctor with her mom. P

She read letters from an eye chart. P

"Well, Jessica. You need glasses," said the doctor. P

Jessica was surprised! "Do I really need glasses?" P

"Your eyesight isn't too bad, but don't watch TV or read books too closely," he said. P

"When you use the computer, take a break every twenty minutes. P

Look far away and slowly move your eyes sideways. P

Eat lots of carrots and spinach, too." P

That night, Jessica wore her glasses and looked in the mirror. P

She liked herself with glasses on, but she was worried a little bit. P

'I must take better care of my eyes,' she thought. P

Her image nodded in the mirror. P

Lesson 8-81

Many people build homes according to their environment. P

In Coober Pedy, Australia, around 4,000 people live in underground homes. P

The cool earth protects them from the 50ºC summer heat. P

In Papua New Guinea, people build wooden houses on stilts. P

The stilts protect the houses from floods. P

In places with a lot of water, people may choose to live on houseboats. P

Houseboats come in many shapes and sizes. P

Some of the simplest houseboats can be found on the Tonle Sap Lake in Cambodia. P

They are made of wood and palm leaves. P

Houseboats in Britain are very narrow. P

This lets them travel along thin canals. P

Despite their small size, they contain a kitchen, bedroom, shower and living room. P

The beds and sofas usually fold up to save space. P

Houseboats in Australia and America can be much larger. P

This is because they are kept on wide rivers and lakes rather than canals. P

Some of the biggest houseboats are called floating mansions. P

They can contain fireplaces, bathtubs and swimming pools! P

They serve as dwellings as well as vacation homes. P

Would you like to live on a houseboat, or would you prefer another kind of special home? P

Lesson 8-82

Do you spend your allowance slowly and carefully? P

Or do you run out of money every week? P

If you answered yes to the second question, then it's time to make a budget. P

A budget is a record of how much money you will receive (your income) P

and how much money you plan to spend (your expenses). P

Here is an example: As you can see above, Lindsey's allowance is $15. P

She also walks her neighbor's dog, and earns $10 per week. P

So her weekly income is $25. P

This week she plans to spend $7 on transportation, $5 on snacks, and $2 on swimming. P

So her expenses will be $14. P

By making a budget, Lindsey knows she will have $11 left over to either save or spend. P

Make a budget at the beginning of each week. P

You should plan your spending carefully. P

Do not forget to include things like a birthday card for your mom or a trip to the movies. P

Lesson 8-83

At the Miteme School in Malawi, children take classes under a tree. P

There are no books, only a blackboard. P

There are not even enough teachers. P

Worse , there is no clean water, so children cannot drink anything. P

As a result, most children simply stay home. P

Of the 500 students, about 100 come to school each day. P

However, UNICEF (the United Nations Children's Fund) offers hope to schools like this. P

Since 2005, UNICEF's Schools for Africa campaign has built or improved around 600 African schools. P

It has given clean drinking water to 151 schools and toilets to 439 schools. P

Nearly every school has been given desks, pencils and books. P

In total, around 3 million students have been helped by the campaign. P

Now UNICEF plans to help the Miteme School. P

"We will improve this school so that children will want to stay here and learn ," explained one UNICEF worker. P

Of course, UNICEF cannot do this alone . P

It needs funding from people like you. P

You can be a part of the campaign by raising money with your classmates. P

With your help, even more African students can have a brighter future. P

Lesson 8-84

As part of his school's "Job Week," Daniel spent a day with a movie director. P

Read about his experience. P

09:30 I arrived at the studio to meet the director, Sophie Yang. P

She was shooting the final scene of her latest movie, A Love Story. P

I was excited to see so many people there, especially movie stars. P

10:00 Sophie began directing the scene. P

She had to guide the actors, control the lighting, and direct the camera people. P

It took a long time. It can take hours to film a five-minute scene in the studio. P

14:00 Finally, we ate lunch. Then Sophie and I went to the editing room. P

There, the editor used a computer to put the scene together. P

First he cut out all the mistakes and then Sophie chose the parts with the best acting. P

She also chose music. "I think Ne-Yo's new song will fit this scene," she said. P

17:00 I went home, but Sophie stayed. P

She said, "Sometimes I work 20-hour days. But I love my job. P

I can turn my ideas into beautiful movies that touch people's hearts. P

Lesson 8-85

A star is a huge shining ball of gas that gives off heat and light. P

Stars fall into various groups according to their size, temperature and lifespan. P

The three main groups are red stars, yellow stars and blue stars. P

Red stars are the smallest. They can be hundreds of times smaller than the Sun. P

They burn their fuel very slowly, so they can live for trillions of years. P

Yellow stars, like the Sun, are medium -sized stars with a medium temperature. P

They can live for about 10 billion years. Blue stars are extremely large. P

They burn their fuel quickly. This makes them very hot. P

These stars only live for about 10,000 to 100,000 years. P

What kind of stars do we see when we look up at the night sky? P

Interestingly, red stars are the most common type of star. P

However, it is difficult to see them because they make very little light. P

Blue stars, on the other hand, are very bright. P

They are rare, but they are the kind of star we see the most. P

Lesson 8-86

In the old television series The Six Million Dollar Man, an astronaut is seriously injured in a crash. P

So, he has an operation that costs $6 million. P

An arm, an eye and both his legs are replaced with machines. P

This gives him super powers, making him a bionic man. P

But did you know that something similar can happen in real life? P

These days, artificial body parts are fairly common. P

For example, a person with an unhealthy heart can be kept alive with an artificial one. P

Or, if someone loses an arm or a leg in an accident, it can be replaced with a robotic one. P

There has even been a man with a bionic brain! P

After an injury to his neck, Matthew Nagle was unable to move his body. P

But doctors placed electronic parts in his brain. P

This allowed him to move a computer cursor just by thinking about it. P

In the future, there will probably be even more uses for bionic body parts. P

Imagine if you had bionic eyes that could see for kilometers or bionic legs that allowed you to jump over buildings. P

What would you do with your new powers? P

Lesson 8-87

The ocean's water levels are constantly changing. At high tide, they rise up. P

During low tide, they sink back down. P

Why does this happen? One reason is gravity. P

Gravity is the invisible force that pulls everything toward the center of the Earth. P

The Moon has gravity, too. P

As it circles the Earth, the Moon's gravity gently pulls everything toward it. P

This pull does not affect the Earth's solid land. P

Water, however, is not so strong. P

The Moon's gravity causes it to bulge out slightly on one side of the planet. P

This is one of the factors that creates tides. P

The Sun's gravity also plays a role. P

The Sun, Moon and Earth form a straight line during the full moon and the new moon. P

This makes the pull of gravity even stronger. P

High tides are higher and low tides are lower. P

These are known as spring tides, although they have nothing to do with the season. P

Without the Earth's gravity, our oceans would float away into space. P

Without the gravity of the Sun and the Moon, we would not have tides. P

Lesson 8-88

Today is my first visit to my friend Alvin's house. P

I am really looking forward to it because Alvin lives under the sea in the Ocean Apartments. P

To go inside, I must take an elevator. P

I press the number of Alvin's apartment. P

Whoosh! The elevator quickly takes me down to more than 100 meters below ground level. P

In front of me is Alvin's front door. I ring the doorbell, and Alvin lets me in. P

His living room windows look out over a beautiful sea garden of colorful coral, rocks and seaweed. P

Eels swim around the rocks. Colorful clownfish and striped angelfish swim through the coral. P

Crabs walk slowly along the bottom. P

"Look, a sea turtle!" I say, as one swims slowly in front of the window. P

Alvin says, "Yesterday some dolphins swam past!" P

After watching for a while, we get hungry. P

Alvin makes a small robot go to the underwater grocery store. P

The robot is a small submarine with space inside. P

Using a remote control, Alvin inputs the food we want, and the robot brings it to us. P

After we eat, it is time for me to go home. P

At home, I remember the beautiful view from Alvin's window. P

Lesson 8-89

Claude Monet was a famous French painter. P

He is best known as an "impressionist. P

" Impressionism is a style of painting that uses quick brushstrokes and bright colors. P

The paintings show the artist's impression of a scene rather than realistic details. P

The word "impressionism" comes from one of Monet's paintings, Impression, Sunrise. P

Impressionists generally painted scenes of nature. P

Like other impressionists, Monet preferred to work outdoors instead of in a studio. P

He was very interested in showing the effects of natural light in his paintings. P

Monet would often paint the same subject several times. P

He would show how it appeared at different points of the day. P

As the sun changed its position, the light on his subject would also change. P

The painting above is named The White Water Lilies. P

It shows a scene from the gardens surrounding Monet's house in Giverny, France. P

It was painted in 1899 on canvas using oil paints. P

This painting is from a series of paintings that Monet made later in his life. P

Despite troubles with his eyes, Monet continued to paint until his death in 1926. P

Lesson 8-90

You want to make beautiful music, but you do not own a violin or a piano. P

Don't worry! You can make your own musical instruments from everyday things in your house. P

Singing Glasses: First, find eight or nine drinking glasses. P

Then fill them with different amounts of water. P

Now, wet your fingertip and gently slide it around the rim of each glass. P

Each one should make a slightly different sound. P

Bottle Rattle: Clean out an empty plastic bottle. P

Now place several small, hard objects inside of it. P

They can be almost anything-buttons, beads, small rocks etc. P

Now, replace the cap. To play your rattle, just shake it! P

Toilet Paper Kazoo: Place a piece of foil over one end of a cardboard toilet paper tube. P

Attach it tightly with a rubber band. P

Now make a small hole in the cardboard just below the rubber band. P

By humming or singing into the open end of the tube, you can make funny sounds. P

If you use your imagination, there are a lot of fun and creative ways to make music at home. P

Now get together with your friends and start your own band! P

Lesson 8-91

Antonio Vivaldi was born in Venice, Italy in 1678. P

Throughout his life he wrote more than 500 concertos. P

He is often called the best Italian composer of all time. P

His most famous work is The Four Seasons. P

It is a dramatic piece that captures the mood of each season. P

The Four Seasons is a set of four violin concertos, one for each season. P

The violin always plays the main solo. P

It is accompanied by other violins, violas, cellos and sometimes a harpsichord. P

Each of the four concertos relates to a season. P

The spring concerto is lively and joyful like the arrival of spring flowers and new life. P

The summer concerto expresses a fierce thunderstorm, with dramatic bass notes* on the cello. P

The autumn concerto is a celebration of the harvest and sounds like the festive songs of peasants. P

The winter concerto brings to mind icy rain with sharp, high notes on the violin. P

Vivaldi composed The Four Seasons nearly 300 years ago. P

However, it is still used today for advertisements, cell phone ring tones and movie soundtracks. P

As a result, you have probably heard a part of The Four Seasons without realizing it! P

Lesson 8-92

"Yuck!" I said. "Look at all those cookie wrappers!" P

My friends and I stared sadly at the pile of trash in the school yard. P

"Why don't students use the trash cans?" asked James. P

"Our school doesn't seem like a cheerful place anymore," said my friend Lucy. P

"Let's do something about it!" We talked about the problem. P

Suddenly we thought of a wonderful idea: to paint a big mural on the outside wall of the gymnasium. P

It would show students how to make our school clean and beautiful. P

First, we explained our idea to the principal. P

"What a great idea!" she said. P

She helped us get materials such as paints, brushes and work gloves. P

The next day, we designed our mural on a piece of paper. P

Then, we started painting it with our classmates. P

It wasn't easy because the wall was so big, but it was fun. P

We were very proud after we finished it. P

The mural shows students picking up trash. P

They are being helped by birds, butterflies and cute squirrels. P

Each day, it reminds students to pick up their trash. P

Now our school yard is cleaner, more beautiful and completely unique! P

Lesson 8-93

Tourists from around the world travel to Pisa, Italy to take photographs of the city's bell tower. P

There are many bell towers in Italy. P

But the Tower of Pisa* is special because it leans at an angle of nearly four degrees! P

The Tower of Pisa was not built this way on purpose. P

When construction began in 1173, there were two big problems. P

First, its foundation was too small. P

Second, the ground it was built on was too soft. P

Before the tower could be finished, it began to lean dangerously to the southeast. P

Construction stopped for nearly 100 years. P

This allowed the ground beneath the tower to harden. P

Later, when builders added more stories to the tower, it began to lean in the other direction! P

The Italian government began to worry that the tower would eventually fall over. P

So they tried many things to stop it from leaning further. P

Finally, it was closed to the public in 1990, and dirt was removed from beneath one side. P

This straightened the tower just enough. P

It was declared to be safe for at least 200 years. P

In 2001, the tower was finally reopened. P

Lesson 8-94

In the 1950s, African Americans began to organize marches and protests. P

They wanted to be treated equally. This was called the civil rights movement. P

One of its greatest leaders was Martin Luther King, Jr. P

King was born in Atlanta, Georgia in 1929. P

He encouraged people of all colors to stand up against racism in a peaceful way. P

In 1955, he led a protest against racist laws in Montgomery, Alabama. P

One law made African Americans sit in the back of public buses. P

So, they refused to ride the buses for more than a year. P

Eventually, King and the other protesters were able to change the law. P

He is best known for his "I Have a Dream" speech. P

It was given in Washington, DC in 1963 after the March for Jobs and Freedom. P

In 1964, he became the youngest person ever to win a Nobel Peace Prize. P

Sadly, Martin Luther King, Jr. was shot and killed in 1968. P

But the civil rights movement continued on stronger than ever. P

He is remembered each January with a national holiday. P

Lesson 8-95

People first started wearing clothes somewhere between 100,000 and 500,000 years ago. P

It is believed that they needed clothes because they started to lose their warm body hair. P

Early clothes were made from animal skin, fur, grasses and leaves. P

People simply tied them around their bodies. P

Then, around 30,000 years ago, people made needles from animal bones. P

They used these to sew leather and fur to make their clothing. P

Around 500 AD, the spinning wheel was invented in Asia. P

This enabled people to spin cotton into thread. P

The thread was woven into comfortable, well-fitting clothes. P

However, spinning and weaving were hard work, so these clothes were rather expensive. P

Only rich people such as kings and queens could afford to own several sets of clothes. P

In the 1800s, the way clothes were made changed completely. P

Thanks to new machines, factories could make clothes quickly and easily. P

Then in the 1930s, cheap materials like nylon and polyester were invented. P

Cheap factory-made clothing flooded the market. P

For the first time, ordinary people could afford to own numerous sets of clothes in various styles. P

Lesson 8-96

Hoyee! My name is Segep. Welcome to our Yurok village. P

Yurok means "downriver people." We live near the beautiful Klamath River in California. P

Every day we catch delicious salmon and mussels. P

Welcome inside our home. It is made from redwood trees. P

Here, have some dried seaweed and acorns. P

Mom will make us some tea from berries. P

Do you see the three lines tattooed on her chin? They are a sign of beauty. P

The tattoos on Dad's arm are a sign of wealth. P

Dad is a canoe maker. He teaches me to fish in his canoe. P

He also teaches me to hunt deer and rabbits with a bow and arrow. P

Mom teaches my sister, Ninowo, to weave baskets from thin branches. P

In our free time, Yurok children play together outside. P

Boys play an energetic game called "tossle." P

Players use a wooden stick to hit a leather ball into a goal. P

We wrestle one another to take the ball. P

My sister plays dice games with her friends using mussel shells. P

Ninowo is 16, so she will get married soon. I'm glad I'm not old enough to marry. P

I would rather play tossle. Come on. Let's play. P

Lesson 8-97

Good afternoon, everybody. Last week a friend asked me an interesting question. P

The question was, "What would you do if you won the lottery?" P

Of course, I immediately thought about all the things I could buy: P

a brand new computer, a trip to Disneyland and so on. P

But later that day I saw something that changed my mind. P

On my way home from school, I passed Clover Street Hospital. P

I was born there 12 years ago. Actually, I was born with a heart problem and nearly died. P

But the amazing doctors and nurses looked after me, and I survived. P

However, the hospital now has a sign outside it. P

The sign says the hospital may close because it does not have enough money. P

At that moment, I knew what I would do if I won the lottery. P

I would give money to the hospital and start a charity to keep it open. P

Of course, I may never win the lottery. P

But I can make the other part of my dream come true: P

I can start a charity for Clover Street Hospital. P

I will hold several charity events here at school this year. P

So, please support me with your help and donations. P

Lesson 8-98

Dear Dayna, I have a little brother who is just four years old. P

He is so cute that everybody adores him. P

And that's the problem! My parents seem to love him the most. P

It makes me jealous. Even worse, they sometimes make me take care of him when they go out. P

Instead of doing my homework or chatting with my friends online, I have to give him all my attention. P

It's not fair! I'm even starting to resent my little brother for it. P

How can I make my parents love me again? Sincerely, Jealous Sister P

Of course your parents love you! P

If they didn't love and trust you, they wouldn't ask you to babysit your brother. P

You shouldn't feel annoyed with your younger sibling. P

Instead, you should feel proud of how responsible you are. P

Remember, he will always look up to you. P

Of course, you can tell your parents that you sometimes feel left out. P

Just because you're not a delightful baby anymore doesn't mean YOU don't need their attention, too. P

Lesson 8-99

Darren is walking through a dark house. Suddenly, he sees something. P

He quickly shoots his gun several times. P

He counts the bodies, and smiles to see that he has killed three people. P

Then his mom yells, "Dinner time!" P

He puts down his computer game controller and runs to eat dinner with his family. P

The Effect of Watching Violence P

Darren is a nice, normal eleven-year-old American boy. P

Yet experts say that by the time he reaches 18 years old, P

he will have seen 40,000 killings on television. P

Furthermore, he will have seen thousands more in computer games. P

According to research, he is more likely to be violent in real life after experiencing violence on screen. P

The effect is the same whether it is a television show, a movie or a computer game. P

Preventing a Violent Future P

TV, movies and games can make violence seem exciting and necessary. P

Worse, computer games offer children higher scores for killing more enemies. P

To prevent a violent society in the future, we must take responsibility. P

Young people can do this by spending less time in front of a screen. P

Also, they can choose TV shows, movies and games which are peaceful, not violent. P

Lesson 8-100

One day, the god Apollo teased tiny Cupid about his size and strength. P

In revenge, Cupid shot Apollo with one of his special love arrows. P

Soon after, Apollo saw a beautiful nymph and instantly fell in love. P

The nymph was Daphne, the daughter of the river god. She was not interested in love. P

She just wanted to spend her days hunting in the woods. P

When Apollo told Daphne how he felt, she ran away. P

Apollo chased after her. Daphne knew she could not outrun a god. P

So, she called out to her father for help. P

Apollo saw Daphne stop running, so he reached out to grab her in his arms. P

But something strange began to happen. P

Her soft skin slowly changed to rough bark, and her long hair became leaves. P

To protect his daughter, the river god had turned Daphne into a laurel tree! P

All that was left was her great beauty. P

With tears in his eyes, Apollo made a crown from her branches. P

"You will never be my wife," he sadly said, P

"but I will wear this crown upon my head to remember you always." P

Daphne, now a laurel tree, shook her branches to show that she was pleased. P

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