2018成人学位英语阅读理解解题方法:因果条件题
(二)条件题型
条件关系通常也是考点，它的主要出现方式如下。
1.以when、if、as等连词引导的条件从句。
2.文章中细节性的条件关系――通常由一些表示条件关系的词汇手段表达：如depend upon(取决于)，determine(决定)等。
例1
wher do pesticides(杀虫剂)fit into the picture of environmental disease? We have seen that they now pollute soil, water, and food, that they have the power to make our streams fishless and our gardens and woodlands silent and birdless. Man, however much he may like to pretend the contrary, is part of nature. Can he escape a pollution that is now so thoroughly distributed throughout our world? We know that even single exposures to these chemicals, if the amount is large enough, can cause extremely severe poisoning. But this is not the major problem. The sudden illness or death of farmers, farm workers, and others exposes to sufficient quantities of pesti-cides is very sad and should not occur. For the population as a whole, we must be more concerned with the delayed effects of absorbing small amounts of the pesticides that invisibly pollute our world.
Responsible public health officials have pointed out that the biological effects of chemicals are cumulative(积累的)over long periods of time, and that the danger to the individual may depend on the sum of the exposures received throughout his life-time. For these very reasons the danger is easily ignored. It is human nature to shake off what may seem to us a threat of future disaster. "Men are naturally mo.st impressed by diseases which have obvious signs,"says a wise physician, Dr. Rene Dubos, "yet some of their worst enemies slowly approach them unnoticed."
People tend to ignore the delayed effects of exposure to chemicals because____.
A. limited exposure to them does little harm to people's health
B. the present is more important for them than the future
C. the danger does not become apparent immediately
D. humans are capable of withstanding small amounts of poisoning
这道题考点涉及原因。如果阅读时圈划了有关因果关系提示词，这道题就比较容易做了。因果关系提示词在第二段第二句：For these very reasons the danger is easily ignored.由此可知本段的前部为答案所在：化学制品的生物作用是长期积累的结果;化学制品对人危害的大小取决于人一生中接收的剂量的多少。C项：“化学制品的危害没有立即显现出来”表达的正是这个意思，所以是正确答案。
例2
It is likely that the dispute regarding flats versus(对，对抗)individual houses will continue to rage on for a long time as far as Britain is concerned. And it is unfortunate that there should be hot feelings on both sides whenever this subject is raised. Those who oppose the building of flats base their case primarily on the assumption(设想)that everyone prefers an individual home and garden and on the high cost per unit of accommodation. The latter ignores the higher cost of providing full services to a scat- tered community and the cost in both money and time of the journeys to work for the suburban resident.
Some people oppose the building of flats because
A. the living expenses for each individual family are higher
B. it involves higher cost compared with the building of houses
C. they believe people like to live in houses with gardens
D. the disposal of rubbish remains a problem for those living in flats
这道题考点同样涉及原因。根据题干中的关键词组0ppose the building of flats定位到含有原因表达法(base…on，意为“以……为根据”)的相关句：Those who oppose the building of flats base their case primarily on the assumption(设想)that everyone prefers an individual home and garden and on the high cost per unit of accommodation.反对建公寓的人主要的根据是，人们都喜欢独居于带花园的住房中，由此可知C项为正确答案。
例3
Even plants can run a fever, especially when they're under attack by insects or disease. But unlike humans, plants can have their temperature taken from 3,000 feet away -- straight up. A decade ago, adapting the infrared(红外线)scanning technolo-gy developed for military purposes and other satellites, physicist Stephen Paley came up with a quick way to take the temperature of crops to determine which ones are un-der stress. The goal was to let farmers precisely target pesticide(杀虫剂)spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest(害虫)problems.
Even better, Paley's Remote Scanning Services Company could detect crop prob-lems before they became visible to the eye. Mounted on a plane flown at 3,000 feet at night, an infrared scanner measured the heat emitted by crops. The data were trans- formed into a color-coded map showing wher plants were running "fevers". Farmers could then spot-spray, using 50 to 70 percent less pesticide than they otherwise would.
The bad news is that Paley's company closed down in 1984, after only three years. Farmers resisted the new technology and long-term backers were hard to find.
But with the renewed concern about pesticides on produce, and refinements in infrared scanning, Paley hopes to get back into operation. Agriculture experts have no doubt the technology works. "This technique can be used on 75 percent of agricultural land in the United States, " says George Oerther of Texas A&M. Ray Jackson, who re- cently retired from the Department of Agriculture, thinks remote infrared crop scan- ning could be adopted by the end of the decade. But only if Paley finds the financial backing which he failed to obtain 10 years ago.
Infrared scanning technology may be brought back into operation because of
A. the desire of farmers to improve the quality of their produce
B. growing concern about the excessive use of pesticides on crops
C. the forceful promotion by the Department of Agriculture
D. full support from agriculture experts
根据题干中的关键词组"brought back into operation"找到原文相关句：But with the renewed concern about pesticides on produce, and refinements in infrared scan-ning, Paley hopes to get back into operation.但是随着人们重新关注杀虫剂对农产品的影响，以及红外线扫描技术的改进，Paley希望能重操旧业。由此可以推出B项为正确答案。这个考点与相关句中的原因状语(以with引导)相联系。
除了上述原文有因果关系提示词的显性原因考点之外，隐性原因(两个句子之间为因果关系，但无有关提示词)也是常见考点。不管考点是显性原因，还是隐性原因，原文相关句出现的格式都是先说原因，后说结果，而在题干中通常给出结果，就其原因提问。
The application of infrared scanning technology to agriculture met with some diffi-culties due to
A. the lack of official support
B. its high cost
C. the lack of financial support
D. its failure to help increase production
这道题测试的考点是一个隐性原因(原文中没有提示词)。相关句为第三段前两句
话：句话提到将红外线扫描技术运用于农业遇到困难――Paley的公司于l984年关闭，第二句话叙述了其中的原因：Farmers: resisted the new technology and long-term backers were hard to find.农场主们抵制这项新技术，而且难以找到(投资方面的)长期支持者。由此可知C项为正确答案。
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