A significant number of complex repair jobs carried out by Ace Repairs have to be reworked under the company’s warranty. The reworked jobs are invariably satisfactory. When initial repairs are inadequate, therefore, it is not because the mechanics lack competence; rather, there is clearly a level of focused concentration that complex repairs require that is elicited more reliably by rework jobs than by first-time jobs.

The argument above assumes which of the following?

1. There is no systematic difference in membership between the group of mechanics who do first-time jobs and the group of those who do rework jobs.

2. There is no company that successfully competes with Ace Repairs for complex repair jobs.

3. Ace Repairs’ warranty is good on first-time jobs but does not cover rework jobs.

4. Ace Repairs does not in any way penalize mechanics who have worked on complex repair jobs that later had to be reworked.

5. There is no category of repair jobs in which Ace Repairs invariably carries out first-time jobs satisfactorily.

这题看了前人的讨论，又反复读了N遍仍然百思不得其解，主要问题有2：

1.E选项怎么翻译？

2.如果将A选项取非，并不能直接使原结论不成立，因为虽然A说两个系统工人不同，但是没有说清是什么不同，即使默认为是技术能力不同，那也没说谁高谁低呀。。。如果first-time job的工人能力高，那不是加强了结论吗？

迷惑～～求解！

问题1。没有哪一类的修理工作（就是说修理工作可能是分类的了的），ACE一上来一次就可以搞定了的。

关于问题2。我觉得您太过于执著了，ASSUME 应该理解为如果取非的话很可能导致原文不成立?不能去细想还分两种情况讨论，考试时时间很短的，都那样想很难做答案。我认为正确的理解是（假如真是要较真）：每次工作都是后面的好，但是先后两次的人并不是固定的。确实有可能第一次的更牛，但是不是每次都摊到的前面的人牛啊，如果下次摊到后面的人牛差，那不是就驳斥了吗？？关键你的理解是把两群人固定了，我认为题目IMPLY 不是这样，是出了事情再分配第二拨人去补祸。都照你那样，老给一拨师傅干补祸的事情，厂长还要不要干了，三个代表还要不要搞了，四个现代化还要不要建设了，全面建设和谐社会还要不要了？？