protection of the environment
     once man did not have to think about the protection of his environment. there were few people on the earth, and natural resources seemed to be unlimited.
      today things are different. the world has become too crowded. we are using up our natural resources,and polluting our environment with dangerous chemicals. if we continue to do this, human life on earth will not survive.
     we realize that if too many fish are taken from the sea, there will soon be none left. yet,with modern fishing methods, more and more fish are caught.we know that if too many trees are cut down, forests will disappear. yet, we continue to use powerful machines to cut down more and more trees. we see that if rivers are polluted with waste products, we will die. yet, waste products are
still put into rivers.
     we know that if the population continues to rise at the present rate, in a few years, there won't be enough food.what can we do to solve these problems?
     if we eat more vegetables and less meat, there will be more food available. land for crops feeds five times more people than land where animals are kept.
     our natural resources will last longer if we learn to recycie them.
     the world population will not rise so quickly if people use modern methods of birth control.
     finally, if we educate people to think about the problems we shall have a better and cleaner planet in the future.

保护环境
    过去，人们不必担心保护环境的问题。  因为那时地球上人口稀少，自然资源似乎取之不尽。
    如今，一切都改变了。世界变得拥挤异常。我们正在耗尽我们的自然资源，有毒化学制品的使用也正污染着环境。如果我们继续这样下去，地球上的生命将不复存在。
    我们都知道如果从海里捕捉太多的鱼，海里就不会再有鱼了。但是，现代化的捕鱼技术使得捕鱼量越来越大。我们都知道如果砍伐太多的树木，森林就会消失。但是，我
们仍旧使用强大的机械砍伐越来越多的树木。我们都知道如果河水被废弃物污染的话，我们只有死路一条。但是废弃物仍然源源不断地进入河里
    我们知道，人口继续照现在这个速度增长的话，不出几年，就会发生食物短缺。我们该如何解决这些问题呢?
    如果我们多吃蔬菜，少吃肉类的话，我们就会有更多的食物。因为同样大小的土地如果种庄稼的话会比养殖动物多养活五倍多的人。
    如果我们学会再利用的话，自然资源就能持续更久。
    如果人们使用现代化的生育控制方法，世界人口就不会增长如此迅猛。
    最后，如果我们能够教育人们都意识到这些问题的话，未来我们就会有一个更好、更洁净的星球。