The world population is rising so quickly that the world has become too crowded.We are using up our natural resources and at the same time polluting our environment with dangerous chemicals.If we continue to do this,life on earth cannot survive.Concerned people have made some progress in environmental protection.Governments of many countries have established laws to protect the air,forests and sea resources and to stop environmental pollution.Still more measures should be taken to solve environmental problems.People should be further educated to recognize the importance of the problems,to use modern methods of birth control,to conserve(保存) our natural resources and recycle（再循环） our products.We are sure that we can have a better and cleaner place in the future.