英语四级写作：全球淡水缺乏

英语自学网

　　It is widely believed that froth water will never be used up because we can get it from rain, rivers and wells. As a matter of fact, such belief is wrong and possibly dan gerous.
        　　Scientists have revealed that despite the fact that the 70% of the earth's surface is covereclwith water, a little part of it is fresh water. Ninety percent of fresh water is stored in the Antarctic zone and cannot be directly used.
        　　Fresh water is used to feed people and propel machines. With the increasing number of the population and factories, the amount of fresh water in use is also growing rapidly. It is estimated that if such growth is not controlled, the fresh water will be used up by the next century. Another dangerous factor is that the water pollution including industrial wastes and poisonous gases which eventually blacken rivers and form acid rains.
        　　We still have time if we act just now. We must tell all the othem the importance of fresh water and the danger we are facing. We can control the number of factories and the wastes they produce. We can also develop new ways to use our limited fresh water more economieally.