一道CR，想不通

Kilroy

Investigators that concluded that human failure was not repsonsible for the fatal air crash last Aug, and since that time new and more strigent rules for identifying and reporting mechanical problems hv been in effect. That accounts for the fact that reports of airplane mechanical problems hv increased in frenqucy by 50 percent since last Aug.
Which one of the following is the an assumption underlying the argument in the passage?
(A) Airplane is still relatively safe, despite the increase in reported mechanical problems
(B) mechanical problems in airplane hv increased in frenqucy dramatically since last Aug.
(C) mechanical problems in airplance hv not increased in frenqucy by 50 percent since last Aug.
(D) Airline are less reluctant to report mechanical problems than they previously were
(E) Mechanical problems in airplanes hv become easier to detect since last Aug.







answer: C
请问怎么解释

tongxun

This is the question that I did not know how to resolve when I practised LSAT。
could anyone give a clear explanation？

qiufeng1990

出事后，制定了很多更严格的规则，导致increased in frenqucy by 50 percent since last Aug
实际没有那末多.

tongxun

qiufeng1990：我当时第一次做的时候选的是E。考虑是规则严厉了，原来忽视的现在也把他当作机械故障。其实，再推理一下，就能的出象你一样的解释了。你比我高！

qiufeng1990

千万万万不要这样说。我还不知道自己几金几量。

tongxun

真的，你来后，帮了我的大忙！！！！

Kilroy

还是不明白！
文中的arugment的主题如果是human failure was not repsonsible for the fatal air crash，答案C还是解释不通

Kilroy

还是不明白！
文中的arugment的主题如果是human failure was not repsonsible for the fatal air crash，答案C还是解释不通

tongxun

文中主要想说的是：出事后，制订了严格的措施，事故报告率增高了50%。后两句才是作者的主题。

c800

qiufeng1990：
Let me have to try to explain it. Hope it helps.

The conclusion is ”human failure was not responsible for the fatal air crash”
The line of reasoning implied “出事后，制订了严格的措施is the only factor” accounts for “事故报告率增高了50%”
To make the reasoning valid, the argument at least have to make an assumption (C) 实际没有那末多.
Without (C), suppose实际mechanical problems > 50%, say 60%, then at least some other factors must account for the additional 10%. If so, the reasoning “措施is the only factor” accounts for “事故报告率增高” is flawed, thus the conclusion ”human failure was not responsible for the fatal air crash” is weakened .