专四专八考试

解析：How much of the earth’s water can m

来源:网考网专四专八 所有评论

【单选题】How much of the earth’s water can man really use


A．He can use nearly 75% of it.
B．He can use about 97% of it.
C．He can use exactly 3% of it.
D．He can use less than 3% of it.


网考网参考答案：D
网考网解析：
[听力原文]14-16 The world is not only hungry, but thirsty for water. That may seem strange to you, since nearly 75% of the earth's surface is covered with water. But about 97 % of this huge amount is sea water, or salt water. Man can only drink and use the other 3%-tile fresh water 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, this small amount of fresh water is still enough for us. But our need for water is increasing rapidly. Only if we take steps to deal with the problem now can we avoid a severe world-wide water shortage later on. One of the first steps is to develop ways of reusing it. Today water is used only once and then discharged into a sewer system, and it eventually returns to the sea or runs into underground storage tanks. But it is possible lo pipe used water to a purifying plant. There it can be filleted and treated with chemicals so that it can be used again. But even if every large city purified and reused its water, we would still not have enough. All we'd have to do to make use of the sea water in, the world is to remove the salt. If we take these steps we'll be in no danger of drying up! [试题分析] 数字信息题。 [详细解答] 录音稿：Man can only drink and use the other 3%．．．And we can not even use all of that，…… document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>

相关推荐

发布评论 查看全部评论