Thousands of years ago, people couldn't live for long. Most people only lived to be twenty-five or thirty years old. 20% of people died before they were twelvemonths old and another 30% could not live to be five years old.

    Today, people can live much longer. One reason is that the water we drink is cleaner. Clean water does not cause diseases（疾病）. Besides, medical treatment is better today. More and more people live to be over eighty.

    Women often live longer than men. For example, in Japan, women usually can live to be eighty-five, but men can only live to be eighty.

    In the future, people will probably live longer than today. Here are many things we can do to help people live longer. For example, we can make sure that everyone has enough medicine to fight against diseases. Also, it is necessary for everyone to have enough to eat. Today many people die because they do not have enough food.

    Once upon a time, there （live） a monkey in the forest. The monkey （climb） up a tree and looked down at the river every day.

    One day, the monkey saw a fisherman （throw） net（网） into the river. Then the fisherman caught fish.

    Two hours later, the fisherman （leave） to have lunch. The monkey climbed down from the tree. He planned （catch） fish like the fisherman did.

    The monkey was quite sure of himself because he good at imitating（模仿）. However, the net wound（缠住） itself around him as soon as he （touch） it. When he tried to get out, he （fall） into the river.

    The monkey should learn how （use） the net before touching it. But it was too late. At last, the monkey （die） in the river.