The world 1 many interesting sounds. Some are unpleasant to our ears while 2 are very pleasant to hear. In single day you probably hear 3 sounds. All sounds are different. Some 4 loud, some sounds are high, others are low, some sounds are useful.

    5 sound we can't talk or listen to each other. The ringing of the alarm clock wakes people up. The hooting（鸣笛声）of a car warns people of danger.

    Some sounds are harmful. When planes fly low 6 the land; the very loud sounds can damage the house. Very loud sound can even make people deaf.

    We know sound travels about one kilometer in three 7. In a thunder（雷）storm you see the lighting first and then hear the thunder. This is because light travels 8 than sound.

    Next time you see lighting count the number of seconds before you hear the thunder.

    Divide（分成）this number 9 3. This will tell you 10 kilometers away the thunder storm is.

    Light travels at a very fast speed. It is about a million times 1 than the speed of sound. You can get some idea of this 2 by watching the start of a race (赛跑). If you stand some distance away from the starter, you can see smoke from his gun before the sound gets to your 3

    This great speed of light4some strange facts. Sunlight 5about 8 minutes to get to us. If you look at the light of the moon tonight, 6 that the light rays (光线) left the moon 1.3 seconds before they got to you. The nearest star is so 7 away that the light which you can see from it tonight started to 8 towards you several years ago. In some cases, the light from one of tonight's stars had started on its journey to you before you were born.

    So, to be exact, we can't say, "The stars are shinning 9." We have to say instead, "The stars 10 pretty. They were shining several years ago, but their light has only just got to the Earth."

    How much do you know about the universe? In the huge universe, there is the Galaxy and many other galaxies. In the Galaxy, there is the Solar System and lots of other stars. In the Solar System, there is the sun, the earth and seven other planets. As we know, the eight planets go around their star —the sun. In our Earth—moon System, the moon goes around the earth. And because our earth keeps turning around the sun all the time, we have day and night. When our part of the earth turns to the sun, it is day. When our part of the earth turns away from the sun, it is night.

    Just because the moon is closer to the earth than the sun, it looks much bigger than the sun. The sun is big enough to give out very strong light. The moon itself can't give any light at all, but it looks quite bright, too. In fact, the light from the moon comes from the sun. Although, the moon looks much bigger and brighter than the sun and other stars, in fact, all the stars are much bigger and brighter than the moon. They look smaller than the moon also because they are farther away from us. It's clear that big things will look smaller when they are farther, and small things look bigger when they are nearer.

So far, we have traveled to many other planets in the universe. But scientists haven't discovered any living things on any other planets. Scientists haven't discovered any other planets with a good environment. They aren't sure if there is any water and air for living things to live on other planets. People always ask the question: Is there anyone out space? Our scientists haven't got a clear answer either. Some people think it will be a secret for a long time. But we believe we can solve the problem some day.

Exploring our Solar System and the universe is a great national project to some countries. Our Chinese scientists are also trying to send spaceships with astronauts to those planets and even the universe. At 9:00 a.m. on October 15th, 2003, a Chinese astronaut called Yang Liwei was sent up to space. He stayed there for hours and got back to the earth at 6:00 a.m. the next day. It was the first time for Chinese to have a space travel.

    Global warming means the temperature of the Earth is getting higher and higher. If the Earth gets 1, some of the following things could happen:

    The sea level could 2 because of the melting of sea ice.

    Many animals that live on the ice might 3 out.

    There could be more floods(洪水), 4 near the sea and rivers.

    Some plants and animals might die because they cannot live in high 5.

    Global warming is a very 6 problem now. There is something we can do to help to slow it down.

    Scientists have been studying global warming for years. They have found that some things that people do in everyday life make much gas that 7 global warming. One big cause of this is the burning of oil, gas and coal for energy for our cars and homes. This gives off too much greenhouse gas. We can do something to cut 8 on the amount of greenhouse gas.

    ⒈ We can really help by using less energy in life, and less gas in our family cars. We should turn off the 9 and turn down other electrical equipment. We should walk more and use cars less.

    ⒉ 10 can take in some of the greenhouse gas. So we should plant more trees.

Situation：Suppose your class are having a discussion about what kind of pen friend you would like to have. Please write about your opinion(s) and give reasons. (假设你们班里正在进行一项讨论，主题是关于希望拥有怎样的笔友，请谈谈你的想法和理由)

Early to bed, early to rise, makes a man healthy, wealthy and wise.

This is an old English saying. Have you heard of it before? It means that we must go to bed early and get up early in morning. Then we shall be healthy. We shall also be rich (wealthy) and clever (wise).

This is true. The body must have enough sleep to be healthy. Children of young age should have ten hours' sleep every night. Children who do not have enough sleep cannot do their work very well. They will not be wise and they may not become wealthy!

The body also needs exercise. Walking, running, jumping, swimming and playing games are all exercise. Exercise keeps the body strong.

Exercise also helps the blood (血液) to move around inside the body. This is very important. Our blood takes food to all parts of our body. The head also needs blood. Exercise helps us to think better!