15.
Some airlines allegedly reduce fares on certain routes to a level at which they lose money, in order to drive competitors off those routes. However, this method of eliminating competition cannot be profitable in the long run. Once an airline successfully implements this method,
any attempt to recoup the earlier losses by charging high fares on that route for an extended period would only provide competitors with
a better opportunity to undercut the airline's fares.
Which of the following, if true, most seriously weakens the argument?
(A) In some countries it is not illegal for a company to drive away competitors by selling a product below cost.
(B) Airline executives generally believe that a company that once underpriced its fares to drive away competitors is very likely to do so again if new competitors emerge.
(C) As part of promotions designed to attract new customers, airlines sometimes reduce their ticket prices to below an economically sustainable level.
(D) On deciding to stop serving particular routes, most airlines shift resources to other routes rather than reduce the size of their operations.
(E) When airlines dramatically reduce their fares on a particular route, the total number of air passengers on that route increases greatly.答案：B。 D的错误我已经知道了。但是我觉得B也不合理。我认为削弱后多应当达到的效果是航空公司能够长期获利。即使像B所说，该航空公司在面临新的竞争者时会故技重施，但是故技重施之后最终还是要提价的，而只要一提价竞争者就又会出现，原题并没有表达出改航空公司故技重施后就会永远地吓跑竞争者，这样公司只能重复不停地故技重施，怎么能够长期获利呢？
请NN指点。 | 
