Theworldisnotonlyhungryitisalsothirstyforwater.Thismayseemstrangetoyousincenearly75％oftheearth'ssurfaceiscoveredwithwater.Butabout97％ofthishugeamountisseawaterorsaltwater.Mancanonlydr

题目详情

　　The world is not only hungry it is also thirsty for water. This may seemstrange to you since nearly 75％of the earth's surface is covered with water. But about 97％ of this huge amount is seawater or salt water. Man can only drink and use the other 3％--the fresh water that comes from rivers lakes underground and other sources. And we cannot even use all of that because some of it is in the form of icebergs and glaciers. Even worse some of it has been polluted.

　　However as things stand today this small amount of fresh water which is constantly being replaced by rainfall is still enough for us. But our need for water is increasing rapidly almost everyday. Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on. A limited water supply would have a bad effect on agriculture and industry. Let me give you just one small example of how necessary water is to industry. Did you know that to produce a single ton of steel it takes about 91000 litres of water?

　　We all have to learn how to stop wasting our precious water. One of the first steps we should take is to develop ways of reusing it. Experiments have already been done in this field but only on small scale. The systems that have been worked out are similar to those used in spacecraft.

(1) “The world...is also thirsty for water.” this means that ________.

[　　]

A．the world has not enough fresh water to meet our future needs

B．people all over the world are thirsty for water now

C．we are now facing a serious problem of world-wide water shortage

D．we cannot make use of all the fresh water on earth

(2) According to the passage only about ________ of the earth's surface is covered with fresh water that can be used.

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A．75％

B．3％

C．97％

D．2 . 3％