Earthquake are common: thousands of them happen each day. But most are too weak to feel. During a 1 earthquake, there is often a great noise first. Then the earth 2 terribly and many houses fall down. Railway tracks break and trains go 3 lines; a great many factories are destroyed; thousands of deaths are caused, and many more lose homes. Besides the great damage and deaths caused by the earthquake 4, other accidents such as fires often 5.

    More buildings are destroyed and more deaths caused.

    It is well-known of the dangers of an earthquake, 6 for centuries man has been making researches on earthquakes. More than 2000 years ago, 7, a Chinese scientist named Zhang Heng invented a machine which could 8 from which direction the seismic waves（地震波）had come, and this machine is still used by scientists today. Now we know much more about earthquake and    9 they happen, but we still can't  10 exactly when and where an earthquake will happen, and can't stop it from happening.

    Natural resources are things that we use that come from the earth. Our natural resources are limited(有限的). This means that they will not1forever. Some are renewable, like when you plant a new tree when you cut one down. Others are not renewable, like when you dig coal(煤) out of the 2Once it is used, it is gone.

    People realize the 3 that the earth's natural resources are limited, and can do things to help conserve(节约) those resources.4you try to conserve a natural resource, you try to use less of it, so it does not get used up so5One way that people conserve fuel, like gasoline, is by riding a bicycle or walking when the6is short instead of driving everywhere.

    Water is a very important natural resource because we all need it to stay 7We can conserve water8making sure that our pipes and taps do not leak(泄露). We can also make wise choices to conserve water, like only using the dishwasher or washing machine when they are full. Everyone can make contributions to protecting natural resources.

    Protecting (保护) wild animals is our duty. Because wild animals are important to us. They live with us on the earth together. If there are no animals on the earth, we will not live on, 1. So we should 2 them to help us live a healthy life.

    3 some people still don't realize the importance(重要性) of protecting wild animals. They often 4 wild animals for food or for money. Every day there are many wild animals being killed. So lots of wild animals are 5. We can't see them anymore. Today the number of wild animals 6 becoming smaller and smaller. If we don't protect them, they will all die out. If this goes on, there will be no animals  7 on the earth.

    8, more and more people began to do many things to help protect wild animals. They ask people 9 wild animals. They get people to know that protecting wild animals is one of the most important things. Now many 10  have made some laws to protect wild animals. Now that (既然) wild animals are so important to man, we should do our best to protect them.            

    Can you imagine what life will be like in the future? Will life in the future be better, worse or the same as now?1do you think of the future?

    People2that life will be probably very different in 2050. First of all, planes will be very3so flying will be very cheap. Everyone will have a small car. Fuel will be new and clean, but expensive. We will4robots everywhere. And space planes will take us around the universe5two hours. Homes will be warm in winter and cool in summer, so they will be very comfortable. We will use the sun6our homes. Computers will be very small so they will be very7. People will do many things on the Internet.

    At that time, water will become one of our most8problems. In many places, farmers will be in great need of water to9fruit and vegetables.

    By 2050, we will be able to help blind and deaf people see again and10again. At that time, our life will become better and better.

    Tigers are strong and dangerous. But now, the big animal is calling for our1.

    There were once eight kinds of2in the world, 3three died out during last century. In the last 70 years, the number of Siberian tigers(东北虎) has gone from as many as 300 to somewhere 418 and 22.

    WWF started a programme recently(最近) to put an end(停止) to tiger poaching(非法狩猎) and 5wild tigers. China, together with 12 other countries, has joined in.

    The Siberian tiger is already6of the world's most endangered(濒危的) animals. If the government doesn't take any action, it's quite7that there will be no more Siberian tigers in China in 10 to 20 years. Animals such as deer, sheep and wild boars(野猪) are the tigers' main food. There isn't enough8for wild tigers because of the hunting of these animals. So the 9 thing people can do is save the animals which tigers eat." To protect the tigers, we need to call on more people to 10 eating and hunting wild animals."