A Thirsty World

　　A Thirsty World 　　The world is not only hungry, it is also thirsty. This may sound strange, since nearly seventy percent of the earths surface is covered with water. But about ninety percent of this is sea water. Man and most of the animals can only drink and use the remaining percent of water--fresh water. 　　The need for water is increasing day by day. Only steps are taken to deal with this problem immediately can we avoid a severe world-wide water shortage later on. One of the first steps is to develop ways to reuse it. 　　Experiments have already keen carried out in this field.The used witer has been pumped to a water-purifying plant.There, it can be separated from waste matter and treated with chemicals so that it can be used again, just as if it were fresh water from a spring. 　　水资源短缺是地球上的一大问题，但作者告诉我们对废水的处理和再次利用可解决此问题，让我们看到希望。 　　干渴的世界 　　这个世界不但缺少粮食，而且也缺少水。这听上去可能有点奇怪。因为地球上几乎70％被水所覆盖。但其中90％是海水。人和大多数动物只能饮用剩余的水淡水。 　　对水的需求与日俱增。只有立刻采取措施解决这一问题才能避免日后全球范围内严重缺水。第一步便是水的重新利用。 　　在这方面已经进行了一些研究。用过的水被抽到净化水的工厂。在那里，水被从废物中分离，然后再用化学物质处理。水便可再次使用，就像泉中的水一样干净。