求助XDF+NN，关于这题我第3次错了，就不知道为啥

alicejingli

想问问大家,
在削弱计划这类题目中，我总区分不清楚到底哪种情况下就因否定了前提计划来排除选项呢？，这个问题希望各位能给我讲讲，每次做题总是在这个方面有问题下面就是体现这个问题的题目
Since the deregulation of airlines, delays at the nation's increasingly busy airports have increased by 25 percent. To combat this problem, more of the takeoff and landing slots at the busiest airports must be allocated to commercial airlines.
Which of the following, if true, casts the most doubt on the effectiveness of the solution proposed above?
(A) The major causes of delays at the nation's busiest airports are bad weather and overtaxed air traffic control equipment.
(B) Since airline deregulation began, the number of airplanes in operation has increased by 25 percent.
(C) Over 60 percent of the takeoff and landing slots at the nation's busiest airports are reserved for commercial airlines.
(D) After a small midwestern airport doubled its allocation of takeoff and landing slots, the number of delays that were reported decreased by 50 percent.
(E) Since deregulation the average length of delay at the nation's busiest airports has doubled.
答案是a。
关于这道题，
目的解决delays
计划增加takeoff + slots
A：我的想法：A选项说天气不好不就是否定了计划（增加takeoffs),有些像老师上课时说的否定了提干前提，那不就不能选这个吗！那为啥还要选这个。请讲讲,我总区分不清楚到底哪种情况下就（因否定了前提计划来排除选项呢？），这个也需要讲讲
B无关
C无关
D支持
E无关

lihaowork

题目问casts the most doubt ，相当于weaken。第一句话是背景，自从deregulation后，飞机晚点增加。第二句话proposed solution是增加slots。此题也可以考假设，即题目预设前提是deregulation导致飞机增加，飞机增加导致lacking slots，再导致了delays。那么削弱它的选项就是说，delay是其他原因造成的，因此选A。
B是加强，C超过六成的slots留给了commercial airlines，超过六成是没有比较的，无法断定是多还是少。如果commercial airlines占全部航线的九成，那么六成的slots是少的，加强了solution。如果commercial airlines只占五成，那么六成过多，又变成了削弱。D显然是加强。E仍然从不同角度重复背景而已。

sdcar2010

Since the deregulation of airlines, delays at the nation's increasingly busy airports have increased by 25 percent. To combat this problem, more of the takeoff and landing slots at the busiest airports must be allocated to commercial airlines.
Which of the following, if true, casts the most doubt on the effectiveness of the solution proposed above?

LZ, you need to understand the argument first.  The argument is not about increasing takeoff or landing slots.  Rather, it is about allocating this task to commercial airlines in order to reduce delays.

A) The delay was caused by weather and hardware.  If this is the case, merely changing the hands operating the air traffic control would not reduce the delay problem.  Hence, this is a weakener.

alicejingli

我还是执着于关于那种情况就是否定前提了？