APP 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 （共 1426 字） [閱讀本文] >>
