Throughout history man has changed his physical environment in order to improve his way of life. With the tools of technology he has altered many physical features of the earth. He has transformed 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 ever before. 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

　　 历史上的人改变了他的物理环境,以改善自己的生活方式。借助技术工具改变了地球的许多自然特征。他将林地和草原改造成为农田,使江河变成湖泊和水库,用于灌溉或用于水力发电。男人也修改了地球表面由高山沼泽和切断山区修建公路和铁路。

　　 然而,人的物理环境的变化并不总是有有益的结果。今天,空气和水的污染是越来越危害地球的健康。每天成千上万吨的机动车辆的排气管排出的气体排放出来。工厂释放的烟雾污染了空气工业化地区和周边地区的农村。水的污染也同样有害。海洋的整个生态平衡正在改变,工业废物已经使许多河流毫无生气。

　　 现在,环境保护比以往任何时候都更为紧迫。正如我们所知,环境的巨大破坏已带来负面影响,甚至对人类造成巨大威胁的存在。对这些问题漠不关心将意味着自杀。因此,应采取有效措施并通过法律来保护环境。不然的话,人类势必遭受缺乏所造成的严重后果关心生存环境