(2)表明因果聯系的動詞：result in(結果)，result from(因為，由……)，follow from(……結果)，base…on…(以……為根底)，be due to(因為);
(4)表明因果聯系的副詞：as a result，consequently等。
2.文章中細節性的條件聯系——一般由一些表明條件聯系的詞匯手法表達：如 depend upon(取決于)，determine(決議)等。
Where do pesticides(殺蟲劑)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 ex-tremely 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(堆集的)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
這道題考點觸及緣由。假如閱覽時圈劃了有關因果聯系提示詞，這道題就對比簡單做了。因果聯系提示詞在第二段第二句：For these very reasons the danger is easily ignored.由此可知本段的前部為答案地點：化學成品的生物效果是長時間堆集的結果;化學成品對人損害的巨細取決于人一生中接納的劑量的多少。C項：“化學成品的損害沒有當即顯現出來”表達的恰是這個意思，所所以準確答案。
It is likely that the dispute regarding flats versus(對，對立)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(想象)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
這道題考點相同觸及緣由。依據題干中的要害詞組0ppose the building of flats定位到富含緣由表達法(base…on，意為“以……為依據”)的有關句：Those who oppose the building of flats base their case primarily on the assumption(想象)that everyone prefers an individual home and garden and on the high cost per unit of accommodation.對立建公寓的人最首要的依據是，大家都喜愛獨居于帶花園的住宅中，由此可知C項為準確答案。
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(紅外線)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(殺蟲劑)spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest(害蟲)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 where 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
依據題干中的要害詞組“brought back into operation”找到原文有關句：But with the renewed concern about pesticides on produce, and refinements in infrared scan—ning, Paley hopes to get back into operation.可是跟著大家從頭關注殺蟲劑對農產品的影響，以及紅外線掃描技能的改善，Paley希望能重操舊業。由此能夠推出B項為準確答案。這個考點與有關句中的緣由狀語(以with引導)相聯系。
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
話：榜首句話說到將紅外線掃描技能運用于農業遇到困難——Paley的公司于l984年封閉，第二句話敘說了其間的緣由：Farmers：resisted the new technology and long—term backers were hard to find.農場主們抵抗這項新技能，并且難以找到(投資方面的)長時間支持者。由此可知C項為準確答案。
For every course that he follows a student is given a grade, which is recorded, and the record is available for the student to show to prospective employers. All this impo- ses a constant pressure and strain of work, but in spite of this some students still find time for great activity in student affairs. Elections to positions in student organizations arouse much enthusiasm. The effective work of maintaining discipline is usually per- formed by students who advise the academic authorities. Any student who is thought to have broken the rules, for example, by cheating has to appear before a student court. With the enormous numbers of students, the operation of the system does in- volve a certain amount of activity. A student who has held one of these positions of au- thority is much respected and it will be of benefit to him later in his career.
American university students are usually under pressure of work because
A. their academic performance will affect their future careers
B. they are heavily involved in student affairs
C. they have to observe university discipline
D.they want to run for positions of authority
本題問的是美國大學生一般接受壓力的緣由。有關句在前兩句話——第二句指出：All this imposes a constant pressure and strain of work…這一切給學生形成繼續的壓力和嚴重……，由此可知緣由在前一句：For every course that he follows a student is given a grade，which is recorded，and the record is available for the student to show to prospective employers.學生上的每門課都有一個分數掛號在冊，而分數能夠由學生拿給將來雇主看。A：“其學業體現會影響其將來的作業”與上句“分數能夠由學生拿給將來雇主看(由其決議是不是選用)”意思共同，為準確答案。榜首句和第二句之間為因果聯系(榜首句為因，第二句為果)，但沒有因果聯系提示詞，依然變成考點，這種先因結果(無提示詞)的構造值得考生留意。
Some students are enthusiastic for positions in student organizations probably because
A. they hate the constant pressure and strain of their study
B. they will then be able to stay longer in the university
C. such positions help them get better jobs
D. such positions are usually well paid
第三句談到有些學生熱衷于在學生安排中任職：Elections tO positions in student organizations arouse much enthusiasm.接著評論了任職學生的效果，最終才說到了學生熱衷于任職的緣由：A student who has held one of these positions of authority is much respected and it will be of benefit tO him later in his career.任職的學生受人敬重，并在將來作業中獲益，由此可知C為準確答案。
The reason these two wonders of nature are so difficult for many adults to explain to children is that they are not very well understood by adults themselves. For exam-ple, did you know that the lightning we see flashing down to the earth from a cloud is actually flashing up to a cloud from the earth? Our eyes trick us into thinking we see a downward motion when it's actually the other way around. But then, if we believed only what we think we see, we'd still insist that the sun rises in the morning and sets at night.
We believe that lightning is a downward motion because
A. we were taught so by our parents from our childhood
B. we are deceived by our sense of vision
C. it is a common natural phenomenon
D. it is a truth proved by science
這依然是測驗隱性緣由的一道考題，思路是在有關結果鄰近找有關緣由。議論“downward motion”的有關句為第三句：0ur eyes trick US into thinking we see a downward motion when it'S actually the other way around.由此可知大家認為閃電由上向下運動，是因為被視覺所騙，因而B項為準確答案。
After the violent earthquake that shook Los Angeles in 1994, earthquake scien-tists had good news to report: The damage and death toll(逝世人數)could have been much worse. More than 60 people died in this earthquake. By comparison, an earthquake of similar intensity that shook America in 1988 claimed 25,000 victims. Injuries and deaths were relatively less in Los Angeles because the quake occurred at 4 : 31 a.m. on a holiday; when traffic was light on the city's highways. In addition, changes made to the construction codes in Los Angeles during the last 20 years have strengthened the city's buildings and highways, making them more resistant to quakes. Despite the good news, civil engineers aren't resting on their successes. Pinned to their drawing boards are blue prints(規劃)for improved quake-resistant buildings. The new designs should offer even greater security to cities where earthquakes often take place. In the past, making structures quake-resistant meant firm yet flexible materials, such as steel and wood, that bend without breaking. Later, people tried to lift a build- ing off its foundation, and insert rubber and steel between the building and its founda- tion to reduce the impact of ground vibrations. The most recent designs give buildings brains as well as concrete and steel supports. Called smart buildings, the structures respond like living organisms to an earthquake's vibrations. When the ground shakes and the building tips forward, the computer would force the building to shift in the op- posite direction. The new smart structures could be very expensive to build. However, that wouldsave many lives and would be less likely to be damaged during earthquakes.
One reason why the loss of lives in the Los Angeles earthquake was comparatively low is that
A. new computers had been installed in the buildings
B. it occurred in the residential areas rather than on the highways
C. large numbers of Los Angeles residents had gone for a holiday
D. improvements had been made in the construction of buildings and highways