单选题 In 1798 the political economist Malthus predicted that in time mankind would face starvation, having outgrown the available food supplies. Today, a century and a half later, there are still experts who forecast the same global disaster unless urgent measures are taken to prevent it. By the end of the present century there may well be over five thousand million people living on this globe, ail increase of over fifty per cent of today's figure. In order to keep pace with this increase in mankind the farmers of the world would have to step up their production of food by at least two per cent every year. Such a rate of increase has never been maintained in any country by conventional methods of agriculture, despite modern mechanization and the widespread use of fertilizers. There are no large worthwhile reserves of potential farmland, remaining, and good fertile land is continually being diverted to industrial use. Moreover, erosion of the soil takes a constant toll. Intensive research, carried out over many years in all manner of climatic conditions, has produced a revolutionary method of growing crops without using any soil at all. Hydroponics, as this technique is called, may well be the answer to all our food worries. Already it has accomplished wonders in producing huge crops. Hydroponics was once a complicated and expensive business; now it is well out of the experimental stage. Labor costs are far lower than when normal methods of agriculture are employed. In fact, it is a completely automatic system. There is no hard manual work, no digging or plowing, and no weeding to speak of. Yields can be far higher than they are in soil.

单选题 Which of the following best sums up the whole passage?

A、 Hydroponics is a new development in agriculture.
B、 Malthus' prediction has been proved to be correct by modern experts.
C、 Hydroponics may be the answer to the world food shortage in the future.
D、 Conventional methods of agriculture should be improved to step up food production by two per cent every year.

【正确答案】 C

【答案解析】解析：文章第一段第一句“In 1798 the political economist Malthus predicted that in time mankind wouldface starvation，having outgrown the available food supplies．”暗含的意思是：人类将面临饥饿危机，所以答案为C。

单选题 The phrase "having overgrown the available food supplies" in the first paragraph implies that______.

A、 the available food supplies will be enough to feed world population
B、 the earth is too exhausted to support its increasing population
C、 world population will grow at a rate faster than food production
D、 food supplies will be too much available for world population

【正确答案】 C

【答案解析】解析：这句话在首段里没有解释，因此要在第二段找线索。第二段说人口增长很快，要满足食物供应，就不得不提高现今的食物生产速度，可知答案应为C选项。

单选题 According to the author, 2 percent annual increase in the production of food can not be achieved. Which of the following is not the explanation he gave for the problem?

A、 There are not enough potential farmland reserves left.
B、 Land is being lost through erosion and industrialization.
C、 Conventional methods of agriculture are still prevailing all over the world.
D、 Modern mechanization and the use of fertilizers are not well popularized in the world.

【正确答案】 D

【答案解析】解析：根据第二段可知，食物生产落后于人口需求至少2％，传统耕种方式、备用耕地不足以及土壤流失都是因素，由此可知答案为D。

单选题 Which of the following statements is not true of hydroponics?

A、 Hydroponics has created wonders in agriculture.
B、 Hydroponics is too complicated and expensive for practical use.
C、 Hydroponics is considered a revolutionary method of agriculture.
D、 Hydroponics has already been employed in food production.

【正确答案】 B

【答案解析】解析：本题考查词义猜测。根据文章最后一段第四句“Hydroponics was once a complicated and expensivebusiness；now it is well out of the experimental stage．”可知，水耕曾经是一项复杂和昂贵的作业方式，但现在它已经是出实验阶段了，即已经大规模使用了。

单选题 Judging from the passage, the most important advantage of hydroponics should be______.

A、 higher yield
B、 lower labor costs
C、 more automation
D、 less hard manual work

【正确答案】 C

【答案解析】解析：根据文章最后一段倒数第二句。“In fact，it is acompletely automatic system．”可知，从通行情况来看，最重要的水耕优势应该是一个自动的系统。