狒狒23

23. On a certain day, nine scheduled flights on Swift Airlines were canceled. Ordinarily, a cancellation is due to mechanical problems with the airplane scheduled for a certain flight. However, since it is unlikely that Swift would have the mechanical problems with more than one or two scheduled flights on a single day, some of the nine cancellations were probably due to something else.

The argument depends on which one of the following assumptions?

A.      More than one or two airplanes were scheduled for the nine canceled flights.

B.      Swift Airlines has fewer mechanical problems than do other airlines of the same size.

C.      Each of the canceled flights would have been longer than the average flight on Swift Airlines.

D.      Swift Airlines had never before canceled more than one or two scheduled flights on a single day.

E.       All of the airplanes scheduled for the canceled flights are based at the same airport.

参考答案：A 采用取非法。

思路：否定More than one or two airplanes were scheduled for the nine canceled flights.将削弱作者的结论。

A：取非削弱

B：无关。

C：无关。

D：无关。

E：无关。

  看了解释还是不太清楚！不是到怎么取非削弱！！ 麻烦大家指点一下

我还是有个疑问:A.      More than one or two airplanes were scheduled for the nine canceled flight为什么说是assumption呢?

"否定More than one or two airplanes were scheduled for the nine canceled flights.将削弱作者的结论"

若是否定它,我理解为:只有一两架飞机被安排在了这9条取消的班次上,那确实能在一定程度上weaken,

为什么肯定了,就是assumption呢?

对呀,我也觉得只能是Weaken,怎么是Assumption呢

对B取非: less than one or two airplanes were scheduled for the nine canceled flight

也就是说,9次航班都可能集中在了一架飞机上

而因为这一架飞机出事故是可能的

所以,就可能没有除了mechanical problems以外的因素影响这9次航班改行了.

从而削若了结论:  some of the nine cancellations were probably due to something else.