节约用水
我们的世界不仅饥饿，而且因为缺水而干渴。对你来说这可能似乎奇怪：因为我们的地球表面75％由水覆盖着。但是，这巨大的数量中97％是海水、或咸水。只有剩下3％
的来自河流、湖泊、地下，和其他来源的淡水供人们饮用、使用。即使如此，这3％的水源我们也不能够完全使用，因为有些淡水是以冰山或冰河的形式存在。更糟糕的是，一些水源已遭受了污染。
然而，尽管按现状看来，这些少量的淡水即使时常转化成雨水的形式，对我们来说，也仍然够用。可是我们对水的需求却日益迅速增长。我们只有现在采取措施解决这一问
题才能避免未来世界范围内的严重水资源缺乏。限量供水会对农业和工业产生不良的影响。我们举个小小的事例就能证明水对工业的必要性。每生产一吨钢材就要消耗91，000升水，你知道吗?
我们必须杜绝对宝贵水资源的浪费。我们应该采取的第一步就是要发展水再利用的方法。该领域的实验已在进行，但是仅是小规模地进行。水资源再利用系统的重要性
Man and His Environment(人和环境)
Man and His Environment
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 reserviors 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.
人和环境
人类有史以来不断改变自然环境，以改善自己的生活方式。人类借助技术工具改变了地球的矶嘧匀惶卣鳌Ｋ值睾筒菰脑斐晌┨铮菇颖涑珊春退猓糜诠喔然蛴糜谒Ψ⒌纭Ｈ死嗷雇ü釉蟮嘏潘⒃涫健⑿藿ü泛吞返确绞剑谋淞说厍虻拿婷病?br />
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