20.The authors purpose in writing the passage is ________.

　　A) to persuade young children not to worry about criticism

　　B) to stress the importance of positive reinforcement to children

　　C) to discuss the skill of combining criticism with encouragement

　　D) to teach young athletes how to avoid burnout

　　Passage Three

　　Humanity uses a little less than half the water available worldwide. Yet occurrences of shortages and droughts (干旱)are causing famine and distress in some areas, and industrial and agricultural by-products are polluting water supplies. Since the worldpopulation is expected to double in the next 50 years, many experts think we are on the edge of a widespread water crisis.

　　But that doesnt have to be the outcome. Water shortages do not have to trouble the worldif we start valuing water more than we have in the past. Just as we began to appreciate petroleum more after the 1970s oil crises, today we must start looking at water from a fresh economic perspective. We can no longer afford to consider water a virtually free resource of which we can use as much as we like in any way we want.

　　Instead, for all uses except the domestic demand of the poor, governments should price water to reflect its actual value. This means charging a fee for the water itself as well as for the supply costs.

【2012年12月英语四级阅读备考：全真试题(5)】相关文章：

★ 2011年最新六级阅读理解练习（3）

★ 2011年最新六级阅读理解模拟练习（73）

★ 2014年大学英语六级阅读的专项练习5

★ 2012年12月英语四六级阅读暑期备考全真模拟题

★ 大学英语四级考试阅读理解练习19篇之吸烟

★ 2010年6月英语六级考试的标准阅读第26的

★ 2012年大学英语六级模拟试题：阅读理解加详细解析

★ 2011年最新六级阅读理解练习（4）

★ 2013年大学英语六级考试阅读的训练题9

★ 英语四六级的阅读考试需要掌握的72个关键句2