Unit 1- Clouds
A clouds is a mass of droplets in the sky. When the sun heats up the Earth, water on the Earth evaporates and becomes a cloud. What happens if a cloud gets big and thick? It rains.Thick clouds are darker than thin clouds. So the sky looks gray right before it rains. Can we grab a cloud? No, we can’t. A cloud consists of water droplets, so we cannot grab a cloud at all. When you touch it, all you can get are wet hands!
Unit 2- Eggs
What is an egg? Birds and fish give birth to many babies at one time. They can do this by laying many eggs at one time. The baby birds or the baby fish stay in eggs until they are ready to be born. What do eggs look like? When you make a fried egg, you can see a yellow part and a white part. The yellow part of the egg becomes a chick. The chick eats the white part until it comes out of the egg.
Unit 3- Plastic
What does the word ‘plastic’ mean? It means ‘changeable’ in Latin. Are there many kinds of plastics? Yes, there are. Plastics differ in colour, shape, thickness, and so on. There are many kinds of plastics, like grocery bags, kid’s toys, drink bottles and clocks. But most of them have the same weakness. Heat! Can you guess what happens if you leave a plastic bag on a stove? It will melt in a few seconds with a bad smell. However, plastic is cheap and very useful for people’s lives.
Unit 4- Blizzards
In summer, we experience hurricanes. When a hurricane comes, winds blow strongly, and it rains a lot. So what happens if we have a hurricane in winter? It is called a blizzard. When a blizzard comes, the temperature is very low. Winds blow strongly with heavy snow. In some areas, blizzards come more often than in other areas. In the United States, northeastern areas, such as New York, Massachusetts, Or Connecticut experience blizzards a lot. Have you ever been in a blizzard? No? Then you are very lucky!
Unit 5- Koalas
A koala is one of the most famous animals in Australia. The koala eats only leaves and lives in trees. It has long arms like a monkey, so the koala can climb tree branches easily. Is the koala a kind of bear? No, it isn’t. It is more like a kangaroo. Like a kangaroo, the mother koala keeps her baby in the pocket of her belly. They sleep for about 16 hours a day. They eat at least 3 hours a day. Koalas are very slow animals.
Unit 6- Fruit
What is a fruit? Why do plants have fruits? Where do fruits come from?A fruit is the house of seeds. Plants grow flowers to make fruits. Fully grown fruits fall down. Then, the seed grows roots under the ground. Then what happens? Another plant grows! Some fruit trees, like apple trees, peach trees,or pear trees have fruits. There is one interesting fact about fruits. Usually seeds grow inside of a fruit. But strawberry seeds grow outside of the fruit.
Unit 7- Batteries
A battery is a box of electricity. It stores chemical energy, and this chemical energy changes into electricity. Can you name the things that need batteries? A clock may need a battery. A car needs a battery to start its engine. Many things around us are useless without batteries. Do you know that batteries were very huge a long time ago? People couldn’t carry batteries because they were too heavy. So scientists developed small batteries. Now we can carry them everywhere!
Unit 8- Cells
Every living thing has at least one cell. Then what is a cell? Every cell works differently, but most cells work to maintain life. Therefore, a cell is often called ‘the building block of life.’ A small house needs a small number of bricks. A big house needs many bricks. Similarly, small organisms need only a few cells. For example, most bacteria have only one cell. But big organisms, like animals or plants, need a lot of cells. How many cells do people have? They have about 100 trillion cells.
Unit 9- Craters
A crater is a big hole in the ground. Volcanic activity can make craters. After a volcano erupts, we see a huge hole on the top of the volcano. If there is no volcanic activity for a long time, snow and rainfall stays inside the hole. Then the hole becomes a huge lake. It is called a crater lake. Diamond Lake in Oregon, U.S.A. is an example of a crater lake. Is there a crater lake in your country? Have you seen any crater lakes before?
Unit 10- giraffes
Can you guess what the tallest animal in the world is? It is the giraffe! How tall is it? A male giraffe is at least three times taller than an adult man. Giraffes have long necks, long legs, and huge eyes. They also have small horns on their heads. What is the use of these horns? When giraffes fight with each other, they use their heads. Horns protect their heads. In Africa, people kill giraffes for food and for their tails. African people believe giraffe tails bring good luck.
Unit 11- Copper
What is the most useful metal? Copper is one of most useful metals in people’s lives. Copper is found everywhere. It delivers electricity very quickly, so every wire is made of copper. Bullets, irons, electric stoves, and pots also contain copper. Copper is not as expensive as silver or gold. People make cheap accessories using copper. Because it has a beautiful color, copper is sometimes used to cover the surface of buildings. Do you know that copper is the first metal people used in history?
Unit 12- The Earth’s Mantle
We are living on the surface of the Earth. So what is inside the Earth? There is a mantle under the surface of the Earth. The mantle takes up about 84% of the Earth. It is a rocky layer, and it covers the core of the Earth. The mantle near the surface is like a bunch of hard rocks, but the mantle near the core is boiling liquid rocks. When a volcano erupts, this boiling mantle comes out. Also, the mantle heats up underground water. Thanks to the mantle, we can enjoy a hot spa!
Unit 13- The Fourth of July
Independence Day is one of the biggest holidays in the United States. It is the day the United States declared independence from Great Britain. On the fourth of July, you can see fireworks and parades everywhere in the U.S.A. Also, there are lots of interesting events on Independence Day. In New York City, you can see a hot dog eating contest every year on the Fourth of July. In 2007, the champion of the contest ate 66 hot dogs in 12 minutes!
Unit 14 – Transportation
What is transportation? It includes cars, subways, buses, trains, airplanes, and ships. What happens if we don’t have any transportation? We have to use our own feet. How did people travel when there were no cars, trains, or airplanes? People used animals for transportation. Horses were the most popular types of transportation around the world. But some countries also used elephants, camels, and dogs. And they still do! Those animals are slower than modern types of transportation, but riding an elephant must be much more fun than driving a car!
Unit 15 – Martin Luther King, Jr.
Have you heard about Martin Luther King, Jr.? He is one of the most famous people in America. He was a preacher, and he tried to fight for the rights of African Americans. He received the Nobel Peace Prize for his efforts. Without using any violence, he persuaded others that all men are equal. Martin Luther King, Jr. was a great public speaker. He changed the life of African American people. When he died, people were really sad. So they decided to make his birthday a national holiday.
Unit 16 – The Grand Canyon
What is the biggest canyon in the United States? It is the Grand Canyon in Arizona. The Grand Canyon National Park is one of the first national parks in the United States. The Grand Canyon was not made in one day. It took six million years to make it! It is 446 km long and 1.8 km deep. A long time ago, Native Americans believed that the Grand Canyon was a holy place. So they visited the Grand Canyon to pray. Now we visit the Grand Canyon to have fun.
Unit 17 – International Festivals
A festival is an event and a celebration by many people. What is an international festival? People from various countries get together and have a festival together. Also, they learn other cultures and eat foreign foods. The United States has many various kinds of international festivals. Every October in North Carolina, U.S.A. people from over fifty countries enjoy folk dances in various traditional costumes. The festival lasts three days. How old is the festival? It is more than 20 years old.
Unit 18 – Pocahontas
Do you know Pocahontas? Who is she? Why is she famous? She was a daughter of one leader of a Native American tribe. She became famous because she got married to an Englishman. After she married, she changed her name to Rebecca. But she is still known as Pocahontas today. How did she and her husband fall in love with each other? Her husband was captured by Pocahontas’ tribe. The tribe tried to kill him, and Pocahontas saved his life.
Unit 19 – Harlem
How much do you know about Harlem? Harlem is a part of Manhattan, New York. A lot of African American people live there now. In 1904, African Americans started to live in Harlem. Some time later, Harlem became the center of African American culture. Jazz, hip hop, rap music, and other famous African American music became popular in Harlem. But there is one thing you have to know about Harlem. If you travel to Harlem, you should be very careful. Why? Because Harlem is also notorious for crimes!
Unit 20 – Generations
What does generation mean? Generation means two different things. First, generation means a group of people who are born and live around the same time. They have similar ages, and they share the same culture. Second, generation also means each stage in a family. For example, a grandmother, a mother, and a daughter are three different generations. Nowadays, a lot of families consist of one or two generations. How many generations are there in your family? Are there a lot of generations in your family?
Unit 21 – Immigrants
Who are immigrants? Some people leave their own country and live in another country. They are immigrants. They are different from travelers. The United States is a country of immigrants. More than 26 million immigrants live in the United States. Who were the first immigrants in the United States? The first immigrants were European Americans. They brought slaves to the U.S. Most of the slaves were African people. Now European Americans, African Americans, and Latin Americans are the majority of the U.S. population.
Unit 22 – Oil
Oil is a very useful resource for humans. It is used to run vehicles, heat houses, and make roads. And it is even used to make clothes and medicine. It is a very important energy resource. Countries in Mid-Eastern Asia have a lot of oil, and Russia, the United States, and some other countries also have oil. We currently use 84 million barrels a day. Scientists expect that we will run out of oil around 2039. Therefore, scientists try to develop other energy resources.
Unit 23 – Hurricane Katrina
What is the name you hate the most? If you ask people in Louisiana this question, they will say Katrina. On the morning of August 29, 2005, people in Louisiana, U.S.A. were frightened. Hurricane Katrina came to Louisiana. The strong wind broke down a lot of houses, buildings, and trees. It also killed many people. But the disaster didn’t end there. The hurricane flooded the whole city of New Orleans. The damage caused by the hurricane was about 81.2 billion dollars. It was the most disastrous hurricane in U.S. history.
Unit 24 – Levees
A levee is a system to control water levels. When it rains a lot, floods can happen. People build walls along rivers or coasts to prevent floods. So a levee is also called a flood bank. People build levees with various things, such as stones, soil, or cement. However, people sometimes pile sandbags in a flood emergency. The parks near seas or rivers also act as levees. How does it prevent flooding? When it rains a lot, the park is filled with water, and this prevents flooding.
Unit 25 – Pictographs
What is a pictograph? A pictograph is a picture that means a word. Where and when do people use pictographs? Traffic signs on streets or rest room signs are pictographs. However, pictographs in mathematics are different. In math, a pictograph is a kind of graph. It uses pictures to show numbers. For example, if there are pictures of two books on a graph, you can say “He bought two books.” It is very easy and quick for people to read a pictograph. Therefore, pictographs are useful when teachers teach young students.
Unit 26 – Octagons
What is a shape that has five lines and five angles? It is a pentagon. What is a shape that has eight lines and angles? It is an octagon. ‘Oct’ means eight, and ‘Gon’ means shape. Do you know what all the angles of an octagon add up to? They add up to 1080o. A regular octagon has eight lines all of the same length and all eight angles are equal. Where can you find octagon-shaped things? How about your ball pens or pencils? They are all octagons. Also, umbrellas and stop signs are octagons.
Unit 27 – Monet
Are you familiar with Monet? Monet was a very famous artist, and a lot of people know about him. There are some interesting facts about him. Let’s find out what they are! Claude Monet was the first impressionist. Impressionists are French artists who lived in the 19th century, and they loved sunlight. They believed sunlight changed the look of objects. What did Monet draw? Monet loved to draw nature. He sometimes sat by a window all day long, and he drew the same scenery over and over again.
Unit 28 – Sculptures
Where can people easily see a sculpture in their life? They usually see a huge sculpture in front of a large building these days. Therefore, it is one of the most common forms of public art. People make sculptures by carving stone, glass, or metal. Sometimes they make sculptures out of soil. Sometimes people build them by piling up various materials. Some artists make sculptures by piling up trash! What do you call people who make sculptures? They are sculptors!
Unit 29 – Handel
What do you know about George Frederic Handel? He was a composer, and he wrote many famous operas. One of his most famous operas is Messiah. He was influenced by the Italian Baroque style. So his music is elegant and grand like Italian old churches. Most of his works have been played in churches, palaces, and many other places. Handel was born in Germany, studied in Italy, and spent the rest of his life in England. He was also famous to other great composers, such as Haydn, Beethoven, and Mozart.
Unit 30 – The Samba
The samba is a popular folk music in Brazil. It came from Africa and Europe. It is not only a symbol for Brazil, but also a symbol for carnival. Every February or March in Brazil, people come out and enjoy a huge party all together. Bands play samba music, and they walk on the streets. Drums, percussions, and guitars play the samba all together. What do people do when they hear samba music? Dance! How do people dance? The samba is a dance for couples, so people need a partner to dance the samba.