April 22 is Earth Day. Everyone on Earth should care about and protect the earth!

The earth has warmed by about 1°F (华氏度) over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. But many scientists say that people are doing many things which make the earth warmer. First, greenhouse effect (温室效应) is a very important reason for the change of the earth. People give out too much energy into the air every year. It makes the earth warmer. Climate (气候) change is another important reason. Sometimes it becomes too hot and sometimes too cold. Sometimes there is too much rain and sometimes too little. The change of the climate makes the earth warmer. In turn, the warmth of the earth changes the climate, too.

When the earth becomes warmer, there may be more rain and a rise in sea level. It will affect the growth of plants, animals and people. On a Pacific island, 100 people have to move to higher ground because the sea is rising. These people can no longer live on the coast. Before that, two islands without people went underwater in 1999. Scientists say that the seas can rise by nearly one meter by 2100.

People can affect the earth's air, land and water. As for us, we can do many things to protect the earth. For example, we can use fridges less. We can tell more people about protecting the earth.

Hands play an important part in our daily life. But do you know which of your two hands you use more? Very few people use both hands equally well. Most of us are right-handed. Only about five people out of a hundred are left-handed. New-born babies can take hold of things with either of their hands, but in about two years they usually use their right hands. Scientists don't know why this happens.

Monkeys are our close relatives in the animal world. Scientists have found that monkeys like to use one of their hands more than the other, but it can be either hand. There are as many right-handed monkeys as left-handed ones. Next time you visit a zoo, watch the monkeys carefully, you will see that some of them will use their right hands and others will use their left hands. But most of the people use their right hands better and this makes life difficult for those left-handed people. We live in a right-handed world.

    Elephants are the largest living animals on land. More than 500 1 kinds of elephants were found on the earth over the last 55 million years. Only 2 kinds are still alive today: the African elephant and the Asian (or Indian) elephant. These elephants can only be found in 3 places. However, the older kinds lived in cold places a long time4. An example is the mammoth (猛犸象) — the largest hairy elephant.

    The mammoth was the largest living elephant, which was about seven tons. 5 the elephants today, mammoths had black or dark brown hairs 6their bodies. All the mammoths had tusks (长牙).

    Scientists found most of the extinct (灭绝的) animals by 7 the fossils, 8 their bones and teeth that could be found. However, mammoths are quite different. During the Ice Age, mammoths died and were covered 9 in the ice. The ice kept them very well. So scientists could find the 10 body of the mammoth.

    Henry is a little fatter than he wants to be.He wants to1. So he is on a diet(节食). He tries2too much and he eats very little sugarbecause it will make him3. He also does exercise every4. He swims very often,5he runs about two kilometres a day. Now heis6than before. Henry's sister, Susan, ishealthier than Henry.7 is also younger and thinner than he is. She does8 every day, too. She doesn't9 muchmeat. But she eats a lot of fruit and10 because she thinks they are better for her health.