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
本题问的是美国大学生通常承受压力的原因。相关句在前两句话――第二句指出：All this imposes a constant pressure and strain of work…这一切给学生造成持续的压力和紧张……，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.学生上的每门课都有一个分数登记在册，而分数可以由学生拿给未来雇主看。A：“其学业表现会影响其未来的工作”与上句“分数可以由学生拿给未来雇主看(由其决定是否录用)”意思一致，为正确答案。第一句和第二句之间为因果关系(第一句为因，第二句为果)，但没有因果关系提示词，仍然成为考点，这种先因后果(无提示词)的结构值得考生注意。
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
第三句谈到部分学生热衷于在学生组织中任职：Elections tO positions in student organizations arouse much enthusiasm.接着讨论了任职学生的作用，最后才提到了学生热衷于任职的原因：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.任职的学生受人尊敬，并在未来工作中获益，由此可知C为正确答案。
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
这仍然是测试隐性原因的一道考题，思路是在有关结果附近找有关原因。谈论"downward motion"的相关句为第三句：0ur eyes trick US into thinking we see a downward motion when it'S actually the other way around.由此可知人们认为闪电由上向下运动，是因为被视觉所骗，因此B项为正确答案。
如上所述，因果关系题的答案有时可依据因果关系提示词圈划或定位找，但更多的时候答案中并无因果关系提示词，但仍表达因果关系。有鉴于此，考生平时有必要注意训练自己的因果关系推理。不过，因果关系题的答案以题干中关键词在原文中的前后句或同一段落内为主。
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(死亡人数)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(蓝图)for improved quake-resistant buildings. The new designs should offer even greater security to cities wher 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
根据题干的提示可知，洛杉矶地震造成的伤亡在第三段谈到：文中分析了l994年洛杉矶地震造成的损失和伤亡比较小的原因是：地震发生在休假日的凌晨，公路上车辆不多，同时由于建筑规程的修改，近20年来洛杉矶城市楼房和公路建筑都加固了，防震性能提高了。因此，只有D项：“城市楼房和公路建筑都进行了改进”与上述意思一致，为正确答案。选项A说“楼房安装了电脑”，这是新近的设计方案，1994年还谈不上，所以不对。选项C说大量居民当时外出度假去了，与原文中提到的“地震发生在休假日的凌晨”不符，所以也不对。
条件句也是一个常见的考点。它在原文出现的模式可以是：条件句+主句，或主句+条件句，但题干通常给出主句的意思，问相关条件。
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