【正文】 bend toward light. Insects fly toward light. Living things also respond in other ways. The leaves on some trees respond to a change in season. In autumn, they change colors and then fall off the branches Animals also respond to a change in season. Squirrels save nuts for the winter. Bears sleep through the winter in a cave. You respond to your environment in many ways, too. You may shiver if you are cold. What other ways do you respond to changes in your environment? 18 Flowering Plants What are the parts of a flower? Flowers can have male parts and female parts. The female parts make eggs that bee seeds. The male parts make pollen. Pollen is a powdery material that is needed by the eggs to make seeds. To make seeds, pollen and eggs must e together. The wind, insects, and birds bring pollen to eggs. Many animals love flowers’ bright colors. They also like a sugary liquid in flowers. This is called nectar. While they drink nectar, pollen rubs off on their bodies. As they move, some of this pollen gets delivered to the female flower parts. Over time, the female parts turn into fruits that contain seeds. Animals often eat the fruits and the seeds pass through their bodies as waste. The animals do no know they are working for the plants by planting seeds as they travel to different places! Useful words and Expressions: 1. flowering 開花的 2. pollen 花粉3. powdery 粉狀的 4. sugar 含糖的，甜的 5. nectar花蜜，甘露 6. rub 磨擦 19 Finding the Direction and Location How can you tell which direction? By day, look for the Sun. It is in the east in the morning and the west in the afternoon. At night, use the Big Dipper to help you find the North Star. It would be better to bring a pass because its needle always points north. How do you know how far you have gone? You could count every step. Each step is about two feet. You’d better wear a pedometer which is a tool that counts steps. If you know where you started, which direction you are heading, and how far you have gone, you can use a good map to figure out exactly where you are. Today there is a new way for travelers to figure out where they are. It is the GPS. It has 24 satellites that orbit the earth and constantly broadcast their positions. Someday you may carry a small receiver as you hike and use GPS to find out if you are there yet! Useful Words and Expressions: 1. dipper北斗七星 2. pass 羅盤 3. pedometer 步數(shù)計(jì) 4. GPS= Global Position System全球定位系統(tǒng) 5. orbit 軌道，繞……軌道而行 6. receiver 接收器 20 Waves How does light get from the sun to the earth? How does music get from the stage to the audience? They move the same wayin waves! Light and sound are forms of energy. All waves carry energy, but they may carry it differently. Light and sound travel through different kinds of matter. For example, light waves cannot move through walls, but sound waves can. That is why you can hear people talking in another room even though you cannot see them. The energy of some waves is destructive. An earthquake produces seismic waves. Catch a wave. Ask a friend to stand a few feet away from you. Stretch a spring between you. Shake the spring to transfer energy to it. What happens? The spring bounces up and down in waves. When the waves reach your friend, they bounce back to you! Light waves travel 300,000 kilometers (186,000 miles) per second! They can also travel through a vacuum. That is why light from the sun and distantstars can travel through space to the earth! Useful Words and Expressions。9 Albert Einstein Albert Einstein was born in Germany in 1879, His father owned a factory that made electrical devices. His mother enjoyed music and books. His parents were Jewish but they did not observe many of the religion’s rules. Albert was a quite child who spent much of his time alone. He was slow to talk and had difficulty learning to read. When Albert was five years old, his father gave him a pass. The child was filled with wonder when he discovered that the pass needle always pointed in the same direction—to be north. He asked his father and his uncle what caused the needle to move. Their answers about magnetism and gravity were difficult for the boy to understand. Yet he spent a lot of time thinking about them. He said later that he felt something hidden had to be behind things. Useful expressions and words1. device 裝置，設(shè)備 leave to one’s own devices 聽任某人自行其是，允許某人按自己的意愿做事She left the child to her own devices for an hour in the afternoon. 她允許孩子在下午有一個(gè)小時(shí)的自由支配時(shí)間。 2. pass 指南針 beyond one’s pass某人力所不及 catch/fetch/take a pass兜圈子，繞道，拐彎抹角 keep sth within pass 把某種事物限制在適當(dāng)?shù)姆秶鷥?nèi) speak within pass 謹(jǐn)慎小心地說 within sb’s pass 某人力所能及的 within the pass of 在……范圍內(nèi) 磁力 10 Private Cars With the increase in the general standard of living, some ordinary Chinese families begin to afford a car. Yet opinions of the development of a private car vary from person to person. It gives a much greater degree of fort and mobility. The owner of a car is no longer forced to reply on public transport, and hence no irritation caused by waiting for buses or taxis. However, others strongly object to developing private cars. They maintain that as more and more cars are produced and run in the street, a large volume of poisonous gas will be given off, polluting the atmosphere and causing actual harm to the health of people. Whether private cars should be developed in Chicago is a difficult question to answer, yet the desire for the fort and independence a private car can bring will not be eliminated11 A Henpecked Husband and His Wife There was once a large, fat woman who had a small, thin husband. He had a job in a big pany and was given his weekly wages every Friday evening. As soon as he got home on Fridays, his wife used to make him give her all his money, and then she used to give him back only enough to b