求教：如何练习判断CR陈述中的重心

ChristinaKK

练习CR的时候，发现自己最常犯的错误是，当CR论述中的重心给理解错了，比如

老prep cr2 15题
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.

我认为的argument反驳的核心是this method of eliminating competition cannot be profitable in the long run， 所以怎么看答案都没有一个对的，因为无论怎么做都不可能profitable，只好选了一个E，毕竟即使在下降price的时候，可以有很多客户，即使是其他竞争对手也降价，我也可以同样再降价，只要customer足够多，profit是可以保证的。

但是答案是B，只能说明argument要反驳的的核心其实是 the reason why this method cann't work，这样看的话，需要反驳的就是其他公司降价会将cutomer抢人，那么B肯定是对的。

常常犯这类把核心弄错的错误，求教高手，如何去分辨，如何练习？
着急等待中.......

naoyixue

http://www.manhattangmat.com/forums/cr-some-airlines-allegedly-reduce-fares-t1832.html

这个解释好

naoyixue

我开始也选了e,后来看了很久别人的解释，又想了想，有点通了， 其实however, this method of eliminating competition cannot be profitable in the long run还是最终结论 （ 支撑这个结论的是下面的原因，别人能降价），但是另外一面，就像b说的，如果很多老板认为曾经降价的今后还会降价 （ in order to drive out the competitor)，那么就不会进来竞争，那么long turn还是受利，其实就是另外一个原因，来支撑. (那个once是一个假设，一个前提，但是这个b的原因直接否认还有竞争者的存在）

memolsh

不知道我想的对不对
文中的结论是this method of eliminating competition cannot be profitable in the long run，原因是后期为了弥补前期的亏损，票价上涨导致竞争者的价格更低····逻辑链是:票价上涨---竞争者优先----不能长时间实行
开始我想D好像是对的·但是仔细看看，就算是转移了资源，但是总的还是亏损了，暗示还是会涨价
A是无关,C是支持，E选项如果摆到以前我一定会选··但是现在看看这个是不行的！！！！因为你加了一个假设就是客人的人数到一定程度，可以弥补亏损！！！！！！！！！！！！这个是不行的····
求指导··我其实也是摸索

memolsh

不知道我想的对不对
文中的结论是this method of eliminating competition cannot be profitable in the long run，原因是后期为了弥补前期的亏损，票价上涨导致竞争者的价格更低····逻辑链是:票价上涨---竞争者优先----不能长时间实行
开始我想D好像是对的·但是仔细看看，就算是转移了资源，但是总的还是亏损了，暗示还是会涨价
A是无关,C是支持，E选项如果摆到以前我一定会选··但是现在看看这个是不行的！！！！因为你加了一个假设就是客人的人数到一定程度，可以弥补亏损！！！！！！！！！！！！这个是不行的····
求指导··我其实也是摸索-- by 会员 memolsh (2012/8/17 12:25:49)

补充··········choice d is irrelevant, because the pasasge and its conclusion aren't at all affected by what the other airlines do if they decide to stop serving some particular route. all that matters is that they decide to stop serving the route; the subsequet decisions are immaterial. 也就是说····d中是因为和原文中未提到···减少航班对亏损的影响~！！！！！！！！！！！！！！！！！！！！！