FeiFei-23 请帮忙解释：

huadan

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.
LS曾经解释过（dreambuilder），可是还是不明白为什么选A。
具体的解题思路是什么呀？(FF给与的解释很含糊）谢谢！

huadan

FF：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。

不明白为什么用取非法；是否还有其他的思路

拾海

对机场及航空公司的运行不是很清楚...
按我自己理解，题干中说“一般一条航线被取消是因为被安排到这条航线上的飞机出现了机械问题“，这里指的是“飞机出现问题”，之后再说了”S航空公司的航线从来不会出多于1到2个机械问题，可能由其他原因引起”。这里的问题是指航线的问题。
A选项，多于1~2架飞机被安排到这9条航线上，该假设就把出现问题的原因转移到了飞机上，而不是S公司的航线问题。若对A取非，“没有任何飞机被安排到这9条航线上”，那么，既然不是飞机的问题，那肯定就是S公司的航线技术问题了，因此也就否定了作者的结论

我的理解是这样的，不知对不对...

huadan

感谢LS

我有个新的想法：

是否可以通过搭桥法，将两个主题（红字的主题联系到一起）：
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.

原Argument解释说是因为机械故障，However否定原Ar后，解释不可能有超过one or two schedule flights on a single day， =>Conclusion：有“其他原因”引起的cancellation。如果Conclusion成立，条件是more than one or two scheduled flights on a single day 不会出现，所以在一天内可以有更多的More than one or two airplane be scheduled to the nine cancellations

不过这种推理是看了答案后才这样想的，确实不知道出题人的思路和目的是什么？

还希望继续讨论

大小李子通吃

关键是看结论前面的这句话：However,作为转折， since it is unlikely that Swift would have the mechanical problems with more than one or two scheduled flights on a single day,从而得出结论： some of the nine cancellations were probably due to something else.
这个就是引子。

amberdeng

我刚开始也不明白，后来想清楚了。
文中scheduled flights 和airplane是两回事。通常，1架飞机一天可以执行若干次航班。
也就是说，如果问题中提到的被取消的9个航班是应该由1、2个飞机来执行的，那么很有可能是由于机械故障。但如果被取消的9个航班是应该由2个以上的飞机来执行，而该航空公司每天最多有1、2个飞机出现机械故障，那么有可能是天气原因等等造成的。

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.
LS曾经解释过（dreambuilder），可是还是不明白为什么选A。
具体的解题思路是什么呀？(FF给与的解释很含糊）谢谢！

-- by 会员 huadan (2010/1/14 16:32:41)

evangelia

谢谢楼上的解释，强.

cybei

我刚开始也不明白，后来想清楚了。
文中scheduled flights 和airplane是两回事。通常，1架飞机一天可以执行若干次航班。
也就是说，如果问题中提到的被取消的9个航班是应该由1、2个飞机来执行的，那么很有可能是由于机械故障。但如果被取消的9个航班是应该由2个以上的飞机来执行，而该航空公司每天最多有1、2个飞机出现机械故障，那么有可能是天气原因等等造成的。

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.
LS曾经解释过（dreambuilder），可是还是不明白为什么选A。
具体的解题思路是什么呀？(FF给与的解释很含糊）谢谢！

-- by 会员 huadan (2010/1/14 16:32:41)

-- by 会员 amberdeng (2010/2/19 21:07:20)

thechooosenone

明白了~感谢~

719870465

一架飞机一天不可能只飞一个航班，飞2、3个航班很正常。一共有9个航班，如果是两架飞机来完成，例如一架飞机飞了5个航班，一架飞了4个航班。如果这两架飞机都坏了，那么这一天的9个航班肯定都飞不了了。而如果由3架飞机来完成，其中两个坏了，还有一个是好的，肯定不至于9个航班都取消。文章说 “因为一天最多只能有两架坏了，那么9个航班都取消肯定是因为其他原因”。如果让这个推理成立，就必须让飞机的个数多于2两个。选A。