求助og13,112...反前提

vampire_lily

The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist.

Which of the following, iftrue, most severely weakens the argument presented above?

(A) Cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically.
(B) Cars and buses are not nearly as fast as the high-speed train will be.
(C) Planes are not a free-wheel system because they can fly only between airports, which are less convenient for consumers than the high-speed train's stations would be.
(D) The high-speed train line cannot use currently underutilized train stations in large cities.
(E) For long trips, most people prefer to fly rather than to take ground-level transportation.

Premise:train is a fixed linear system,consumers will choose the free wheel systems(cars,buses,aircraft)
conclusion:train will not have market

削弱火车不是没有市场，C的话难道不是反前提吗。。。提前中说了aircraft就是freewheel啊
A的话指出两者差别就意味着在某些方面火车优于其他所以会有市场啊

求解释

Margaret-09

题目说火车没有市场是因为固定路线，而飞机想飞哪里飞哪里。
c选项说飞机不是飞哪里都可以，要有机场才行，而且机场的地点往往不如火车站方便

frank0401

建议你看一下http://forum.chasedream.com/thread-837431-2-1.html