请教prep 1-63

63.   (34945-!-item-!-188;#058&007591)

Companies O and P each have the same number of employees who work the same number of hours per week.  According to records maintained by each company, the employees of Company O had fewer job-related accidents last year than did the employees of Company P.  Therefore, employees of Company O are less likely to have job-related accidents than are employees of Company P.

 Which of the following, if true, would most weaken the conclusion?

 Which of the following, if true, would most weaken the conclusion?

 (B)Company P considered more types of accidents to be job-related than did Company O.

(C) The employees of Company P were sick more often than were the employees of Company O.

(D) Several employees of Company O each had more than one job-related accident.

(E) The majority of job-related accidents at Company O involved a single machine.

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答案是B.想不明白阿。。。我觉得B不是在加强结论么？

看看是不是把题目理解错了：题目的推理是这样的，O和P的员工数相同，每周工时数相同。从事故记录来看，去年发生在O的员工身上的工作事故比发生在P的员工身上的少。所以题目就认为O的员工比P的员工更安全（O的员工发生工作事故的可能性更小）。然后问削弱。

B的逻辑就在于：因为题目中有一个细节——records maintained by each company，也就是说工作事故记录是两个公司自己做的，而不是出自一个独立的第三方。这样做的后果就是，由于两者统计口径的不一致和对“事故”定义的不一致，就会使据此作出的结论出现判断上的偏差。

再看就清楚了吧，如果P对于“工作事故”的定义更严，就会把更多在O不被当作事故的事件记入其事故记录，造成P的事故记录多于O，进一步推论，如果O也采用P的事故定义，说不定统计出来的事故比P更多，则结论显然就不成立了。