大家帮我看看这道逻辑题吧，绕晕了

davidaurora

Although the discount stores in Goreville's central shopping district are expected to close within five years as a result of competition from a SpendLess discount department store that just opened, those locations will not stay vacant for long.In the five years since the opening of Colson's, a nondiscount department store, a new store has opened at the location of every store in the shopping district that closed because it could not compete with Colson's.

Which of the following, if true, most seriously weakens the argument?

a)Many customers of Colson's are expected to do less shopping there than they did before the SpendLess store opened.

b)Increasingly, the stores that have opened in the central shopping district since Colson's opened have been discount stores.

c)At present, the central shopping district has as many stores operating in it as it ever had.

d)Over the course of the next five years, it is expected that Goreville's population will grow at a faster rate than it has for the past several decades.

e)Many stores in the central shopping district sell types of merchandise that are not available at either SpendLess or Colson's.

答案选择B我没有异议，因为其他选项基本不沾边，但是这个这道题的逻辑是什么我基本没理解，前面说两个折扣店比较，后面又说两个非折扣店比较，到底这道题目想说什么呢？B答案是怎么削弱的呢？大牛给指点一下吧，不胜感激。

jiangliu

先不说这题的逻辑，先从语法（SC）的角度来看看这句话：
In the five years since the opening of Colson's, a nondiscount department store, a new store has opened at the location of every store in the shopping district that closed because it could not compete with Colson's.

这里这个a new store 指的是谁？如果他指的是colson's, 那这句话更应该是in the five years since its opening, Colson has opened ...

其次，后边的这个it指的是谁？很明显他不是colson's， 但是他跟前面的那个a new store又有啥关系？

还有，根据时态， 我觉得无法判断现在这个a new store是开的还是关的.

davidaurora

是啊，我就是没看明白，这个a nondiscount department store是指前面的C商店，还是指后面的a new store，大牛给解释一下呗？

cosuede

a nondiscount department store指C，a new store指在C开业后那些空地上开业的商店

jiangliu

知道答案后倒是可以倒推回去,但是要在考试只有2分钟做这题的话估计就不知道啥结果了.

大致的意思是: 后边那个premise说的是新开的nondiscount 店都打不过Colson's， 所以潜意识里也就是说要开新店，那只能是discount店。

然后这个题的argument是：those locations will not stay vacant for long。 如果这个argument成立的话，也就是说会有大批 的discount店来填补这个vacant。

按照B所说的，近来开的都是discount店，所以也就是说你再开discount店已经没有优势了，所以这个地方只能还是vacant的。

酒精灯

尽管G-dis因为拼不过S-dis要关门了，但G-dis腾出来的店铺不会闲置很久。

--类比--

自从五年前C-nondis开张，每一家因为拼不过C-nondis而关门的nondis店（腾出来的店铺都没有闲置很久，）而是有一家新店在那个位置开张了。

--weaken--

取代“因为拼不过C-nondis而关门的nondis店”的不是nondis店，而是dis店；other nondis因为拼不过C-nondis而没了。

--类比--

取代“因为拼不过S-dis而关门的dis店”的也不会是dis店；other dis因为拼不过S-dis而要没了~~

matthew0826

深奥。。

fnm07052

这个题要分清前提和结论
前提有两个，1 Although the discount stores in Goreville's central shopping district are expected to close within five years as a result of competition from a SpendLess discount department store that just opened 虽然在G商业中心的折扣商店在预期的五年里会关闭因为S折扣商店开门营业了

2In the five years since the opening of Colson's, a nondiscount department store, a new store has opened at the location of every store in the shopping district that closed because it could not compete with Colson's 因为在这五年里面C非折扣商店的营业，那些新开的店会占据那些折扣商店关闭的店面位置
结论 those locations will not stay vacant for long 空着的位置不能空很久
怎么削弱呢，这里有一个预先设置的假设，就是在折扣商店关门后，增加在原位置上的是非折扣商店，也就是C商店，因为C商店的开门才会使得这些地没有空着，但要是不是非折扣商店的话，这块地就有可能空着也有可能不空着了，所以b就削弱了这个结论

kaipiggy

没明白。。。。。。。

VivienZheng

知道答案后倒是可以倒推回去,但是要在考试只有2分钟做这题的话估计就不知道啥结果了.

大致的意思是: 后边那个premise说的是新开的nondiscount 店都打不过Colson's， 所以潜意识里也就是说要开新店，那只能是discount店。

然后这个题的argument是：those locations will not stay vacant for long。 如果这个argument成立的话，也就是说会有大批 的discount店来填补这个vacant。

按照B所说的，近来开的都是discount店，所以也就是说你再开discount店已经没有优势了，所以这个地方只能还是vacant的。

-- by 会员 jiangliu (2010/5/26 15:02:49)

jiangliu正解，以下是引用manhanttan review上的解释。
“See the argument basically says this:

5 yrs back a non-discount store opened which led to several stores shutting down (must be selling similar products as the argument says they couldn't compete with Colson). But a new store opened everytime an existing store shut down.

Based on this evidence the author concludes that the same trend will continue now, when Spendless has opened.

But option B gives you a reason why the new stores that opened 5 yrs back managed to survive (because they were discount stores as compared to Colsons which was a non-discount store); it's obvious the same reason will not apply in the current case since Spendless is itself a discount store so why will more new discount stores open if the existing ones are unable to compete with Spendless.”