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。 我想问一下,对于A选项如何取非?是什么意思,为何削弱???(看不懂........)
34. Which one of the following is an assumption on which the conservationist’s reasoning depends?
A. The wildflower currently reproduces only by forming seeds. B. The domesticated daisy was bred from wild plants that once grew in the wildflower’s range. C. Increasing the population of the wildflower will also expand its range. D. Wildflower-daisy hybrids will be able to reproduce. E. The domesticated daisy will cross-pollinate with any daisy like plant.
思路:not+weaken。根据原命题成立则逆否命题成立的原理,把选项取非后,若能对文章产生削弱作用的,则为答案。 A. 与结论无关。另外也可以根据极端词only来进行排除。 B. 就算daisy不是in wildflower's range,wildflower-daisy hybrids也是in wildflower's range。 C. 无关。 D. 把选项取非,变成:wildflower-daisy hybrids不能再繁殖。这样的话,总有一天,随着wildflower的消失,wildflower-daisy hybrids也会消失的,这样就不能达到prevent total loss of the wildflower in its range的目的了,从而也对结论进行了削弱。因此D为答案。 E. 无关。 A选项取非以后不应该是NOT ONLY 以这种方式,即除了forming seeds以外还可以以其他的方式来reproduce,这样不就是对结论的削弱吗?为什么A不对?极端词在这里能用吗?
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