Throughout history man has changed his physicai environment in order to improve his way of life.With the tools of technology he has altered many physical feathures of the earth.He has transtormed woodlands and prairies into farms and made lakes and reservoirs out of rivers for irrigation purposes or hydroelectric power.Man has also modified the face of the earth by draining marshes and cutting through mountains to build roads and railways. 　
　
　　However,man"s changes to the physical environment have not always had beneficial results.Today,pollution of the air and water is an increasing danger to the health of the planet.Each day thousands of tons of gases come out of the exhausts of motor vehicles.Smoke from factories pollutes the air of industrialized areas and the surrounding areas of the countryside.The pollution of water is equally harmful.The whole ecological balance of the sea is being changed and industrial wastes have already made many rivers lifeless. 　
　
　　Now environmental protection is more pressing than everbefore.As we know,massive destruction of environment has brought about negative effects and even poses a great threat to man"s existence .Indifference to these problems will mean committing suicide.Therefore,effective measures should be taken and laws passed to conserve environment.Otherwise,man is certain to suffer from the serious consequences caused by this lack of care for his living surroundings. 　
譯文：人類有史以來不斷改變自然環境，以改善自己的生活方式。人類借助技術工具改變了地球的許多自然特征。他將林地和草原改造成為農田，使江河變成湖泊和水庫，用于灌溉或用于水力發電。人類還通過給沼澤地排水、鑿石劈山、修建公路和鐵路等方式，改變了地球的面貌。 　
　
　　然而，人類改變自然環境并不總是帶來有益的結果。今天，空氣和水的污染給地球的健康造成越來越嚴重的危害。每天機動車輛的排氣管排出成千上萬噸廢氣。工廠釋放的呀呢污染了工業區和周圍鄉村的空氣。水污染同樣有害，海洋的整個生態平衡正在受到破壞，工業廢水已經使許多河流的生物死亡。 　
　
　　現在，環境保護比以往任何時候都更為緊迫。我們知道，對環境的大規模破壞已經帶來負面影響，甚至嚴重威脅到人類的生存。對這些問題漠不關心將意味著自我毀滅。因此，應采取有效措施并通過法律來保護環境。不然的話，人類勢必遭受因其不關心生存環境而引起的嚴重后果之苦。