例4

　　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(xué)生通常承受壓力的原因。相關(guān)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(xué)生造成持續(xù)的壓力和緊張……，由此可知原因在前一句：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(xué)生上的每門課都有一個分數(shù)登記在冊，而分數(shù)可以由學(xué)生拿給未來雇主看。A：“其學(xué)業(yè)表現(xiàn)會影響其未來的工作”與上句“分數(shù)可以由學(xué)生拿給未來雇主看(由其決定是否錄用)”意思一致，為正確答案。第一句和第二句之間為因果關(guān)系(第一句為因，第二句為果)，但沒有因果關(guān)系提示詞，仍然成為考點，這種先因后果(無提示詞)的結(jié)構(gòu)值得考生注意。

　　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

　　第三句談到部分學(xué)生熱衷于在學(xué)生組織中任職：Elections tO positions in student organizations arouse much enthusiasm.接著討論了任職學(xué)生的作用，最后才提到了學(xué)生熱衷于任職的原因：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(xué)生受人尊敬，并在未來工作中獲益，由此可知C為正確答案。

　　例5

　　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

　　這仍然是測試隱性原因的一道考題，思路是在有關(guān)結(jié)果附近找有關(guān)原因。談?wù)摗癲ownward motion”的相關(guān)句為第三句：0ur eyes trick US into thinking we see a downward motion when it'S actually the other way around.由此可知人們認為閃電由上向下運動，是因為被視覺所騙，因此B項為正確答案。

　　如上所述，因果關(guān)系題的答案有時可依據(jù)因果關(guān)系提示詞圈劃或定位找，但更多的時候答案中并無因果關(guān)系提示詞，但仍表達因果關(guān)系。有鑒于此，考生平時有必要注意訓(xùn)練自己的因果關(guān)系推理。不過，因果關(guān)系題的答案以題干中關(guān)鍵詞在原文中的前后句或同一段落內(nèi)為主。

　　例6

　　After the violent earthquake that shook Los Angeles in 1994, earthquake scien-tists had good news to report: The damage and death toll(死亡人數(shù))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(藍圖)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

　　根據(jù)題干的提示可知，洛杉磯地震造成的傷亡在第三段談到：文中分析了l994年洛杉磯地震造成的損失和傷亡比較小的原因是：地震發(fā)生在休假日的凌晨，公路上車輛不多，同時由于建筑規(guī)程的修改，近20年來洛杉磯城市樓房和公路建筑都加固了，防震性能提高了。因此，只有D項：“城市樓房和公路建筑都進行了改進”與上述意思一致，為正確答案。選項A說“樓房安裝了電腦”，這是新近的設(shè)計方案，1994年還談不上，所以不對。選項C說大量居民當時外出度假去了，與原文中提到的“地震發(fā)生在休假日的凌晨”不符，所以也不對。

　　條件句也是一個常見的考點。它在原文出現(xiàn)的模式可以是：條件句+主句，或主句+條件句，但題干通常給出主句的意思，問相關(guān)條件。