第60题~~61. Investigators concluded that human failure was not responsible for the fatal airplane crash last August, and since that time new and more stringent rules for identifying and reporting mechanical problems have been in effect. That accounts for the fact that reports of airplane mechanical problems have increased in frequency by 50 percent since last August.
Which one of the following is an assumption underlying the argument in the passage?
(A) Airplane travel is still relatively safe, despite the increase in reported mechanical problems.
(B) Mechanical problems in airplanes have increased dramatically since last August.
(C) Mechanical problems in airplanes have not increased by 50 percent since last August.
(D) Airlines are less reluctant to report mechanical problems than they previously were.
(E) Mechanical problems in airplanes have become easier to detect since last August.
我的理解：题干是说“new and more stringent rules 从去年8月生效”这一事实能够解释为什么reports of airplane mechanical problems 增加50%。所以必然rules对于mechanical problems产生了影响。
C：mechanical problems本身没有增加50%。可因为有了这个rules，很多mechanical rpoblems就被“identify and report"了。所以C说明不是事故本身增加50%，而是rules的作用。对C取非，则原argument不成立。
B: 对B取非，argument依然成立伐……而且，一个小小的规律是貌似这种用词很绝对的情况，比如dramatically什么的，一般都要警惕呢。
