Unit 1. Weather 1. In other words, weather is what the sky and air are like. 2. The sun warms the air and changes the temperature, which is how hot or cold the air is. 3. Climate tells us what kinds of weather usually happen in an area at different times of the year. 4. People try to use these measurements to figure out what the weather will be in the future.
Unit 2. Rain, Snow, and Clouds 1. Rain is made of very small drops of water, and snow is from very small pieces of ice that form naturally. 2. As the sun warms water, some water turns into vapor: a mass of small drops of water which go into the air. 3. The drops of water and crystals of ice fall back down to the ground as rain, snow, sleet, or hail.
Unit 3. Spring and Summer 1. Spring is when leaves and flowers appear. 2. In spring, the weather gets warmer because the earth is tilted toward the sun. 3. Sunlight and rain help plants grow in spring. 4. In some places, summer is the wettest season with the most rain, and in other places, it is a dry season.
Unit 4. Fall and Winter 1. Fall is a time for harvesting most crops in many places. 2. Fall lasts about the same amount of time as spring but is much shorter than summer and winter in length. 3. In fall, most animals look for food so that they can store it for winter. 4. In winter, some plants die because of the reduced sunlight and cold temperatures.
Unit 5. The Sky Above 1. A molecule usually consists of two or more atoms. 2. The sky appears blue because of the scattering of sunlight by the molecules. 3. They look much smaller than they are because they are far away from the earth. 4. The moon rises and sets in the sky.
Unit 6. Planets 1. A light in the night sky that looks bigger or brighter than the other stars might be a planet. 2. A planet is a large object that orbits the sun, and it does not make light. 3. Pluto used to be known as a planet, but in August 2006, the International Astronomical Union decided it was a dwarf planet instead. 4. Mercury is the closest to the sun, and Neptune is the farthest from the sun.
Unit 7. Leaders and Governments 1. To vote means to choose for or against someone or something. 2. The time when we vote is called an election. 3. Usually, these people are appointed by elected leaders. 4. The mayor makes sure that people follow the city s laws.
Unit 8. The Capital and the White House 1. Washington was named after the first U.S. president, George Washington. 2. The D.C. stands for District of Columbia, a special area that is not a state. 3. A monument is a building or statue that shows special respect for a person or an event. 4. Congress is the part of the government that makes laws for the country.
Unit 9. Taxes 1. The colonists were proud to be English and to be ruled by King George III. 2. The king ordered them to pay taxes on things like sugar, stamps, and paper. 3. When the colonists bought some paper, they paid what the paper cost. 4. At this time, King George III needed lots of money because England had just finished fighting a very expensive war against France.
Unit 10. A Nation Is Born 1. In 1776, the English colonists in America took a very big step. 2. They told King George that Americans wanted to be free and to start their own country a country called the United States of America. 3. On the fourth of July in the year 1776, many American leaders signed the Declaration of Independence.
Unit 11. George Washington 1. He led the American army during the American Revolutionary War and later became the new republic s first president. 2. Each colony sent men who wanted to help fight for liberty, but these men were not soldiers. 3. For eight years, General Washington commanded the American soldiers against the mighty British army, and he led them to victory. 4. He was admired and praised by every American.
Unit 12. Benjamin Franklin 1. When he was still a young man, he started a printing business, published a newspaper, and taught himself to read four different languages, including French. 2. Benjamin Franklin was one of the American leaders who signed the Declaration of Independence. 3. The Americans hoped that Franklin could get the French to help them in their fight against the British.
Unit 13. The Three Little Pigs 1. He blew down the straw house and ate up the first little pig. 2. Next, the wolf went to the house of sticks and down fell the house. 3. Now, the wolf tried in vain to blow down the strong brick house. 4. The wolf landed in the fire and was burned so badly that he ran away for good.
Unit 14. The Blind Men and the Elephant 1. There were six blind men who went to visit an elephant. 2. The second man, standing near the elephant s head, put his hand on its long, sharp tusk. 3. The fourth man touched the elephant s ear and said, The elephant is actually similar to a fan. 4. The startled man pushed the trunk away and said, The elephant is really like a very large snake! ( 해석 )!
Unit 15. Opera 1. An opera is like a play in which everything is sung instead of spoken. 2. In an opera, the actors sing and act out the story on the stage, too, but they do not speak any lines. 3. Many operas were written by composers who lived in European countries, such as Italy, Germany, and France. 4. But because the singing and music are so beautiful, many people love to listen to operas even if they do not understand the words.
Unit 16. Ballet 1. In a ballet, there is music, often played by an orchestra, but no one sings or talks. 2. Some ballets tell stories you may know, like the story of Sleeping Beauty. 3. Ballet dancers have to practice for years to learn all they need to know. 4. They have to work at balancing themselves and controlling their bodies.
Unit 17. Self-Portraits 1. Sometimes an artist paints a portrait of himself. 2. The Dutch painter Vincent van Gogh painted 37 self-portraits. 3. This one, called Self-Portrait, shows him when he was 36 years old. 4. In this painting, called Triple Self-Portrait, Rockwell has fun with the idea of painting a picture of himself.
Unit 18. Still Lifes 1. It is called a still life because the objects in the painting do not move. 2. Still-life painting has been popular since the 17 th century, when Dutch painters raised it to a fine art. 3. To paint a still life, an artist first has to decide what objects to paint. 4. Once the artist knows what to paint, he or she has to decide how to arrange the objects.
Unit 19. How to Tell Time 1. When the minute hand moves from one number to the next, 5 minutes have passed. 2. Another way of writing 35 minutes after 5 is 5:35. 3. 3:15 means 15 minutes after 3. 4. On this clock, it is 30 minutes after 2, or 2:30.
Unit 20. The Calendar 1. A calendar is a set of pages that show the days, weeks, and months of a particular year. 2. You usually hang it on a wall. 3. January is the first month of the year, March is the third month of the year, June is the sixth month of the year, November is the eleventh month of the year, and December is the twelfth month of the year. 4. Learn to say the ordinal numbers from thirteenth to thirty-first in order.