The world is not only hungry, but it is also thirsty for water. This may seem strange to you, since nearly 70 percent of the ear

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问题     The world is not only hungry, but it is also thirsty for water. This may seem strange to you, since nearly 70 percent of the earth’s surface is covered with water. But about 97 percent of this huge amount is sea water , or salt water. Man can only drink and use the other 3 percent fresh water from rivers, lakes, underground , and other sources. However we cannot even use all of that, because some of them are in the form of icebergs and glaciers(冰川). Even worse, some have been polluted.
    However, as things stand today, this small amount of fresh water is still enough for us. But our need for water is increasing rapidly almost day by day. Only if we take steps to deal with this problem now can we a-void a severe worldwide water shortage later on.
    We all have to learn how to stop wasting our valuable water. One of the first steps is to develop ways of reusing it.
    Today in most large cities, water is used only once and then sent out into a sewer system. From there it returns to the sea or runs into underground storage tanks. But it is possible to pipe used water to a purification(净化)plant. There it can be treated with chemicals so that it can be used again, just as if it were fresh from a spring.
    But even if every large city purified and reused its water, we still would not have enough. All we’d have to do is to make use of the vast reserves of sea water in the world and is to remove the salt. If we take these steps we’ll be in no danger of drying up.
To reuse water, we should______.

选项 A、treat it with chemicals
B、use it only once
C、send it out into a sewer system
D、make it flow into underground tanks

答案A

解析 事实细节题。见文章第四段第四句。
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本试题收录于: 英语题库普高专升本分类
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