GWD4中的一个逻辑题,请高人指点

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?

1. Many customers of Colson’s are expected to do less shopping there than they did before the SpendLess store opened.
2. Increasingly, the stores that have opened in the central shopping district since Colson’s opened have been discount stores.
3. At present, the central shopping district has as many stores operating in it as it ever had.
4. 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.
5. Many stores in the central shopping district sell types of merchandise that are not available at either SpendLess or Colson’s.

题意，在G附近的打折商店可能因为在同一地区开了一家新的打折商店，五年内要关门。

自从Colson’s（一家非打折商店）开业5年来，开了一家新店。这家新店呢，开在了一个比较晦气的地方，这个地方所有和Colson’s竞争的商店都关门了，因为竞争不过Colson’s。

问weaken，题目的意思是这家新店也要关门，找个理由说它不会关门就weaken了。

B：开的新店是打折商店。－－－正确

因为前面的背景信息说：同一类型的商店竞争可能会关门。Colson’s（一家非打折商店），新开的是打折商店，定位不同，自然不会竞争，从而关门。

A：无关，提到了消费者

C：反对题意，明明都关门了

D ：和G没关系

E：具体的商品，并为提及

文章后半句：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.

自从Colson’s（一家非打折商店）开业5年来，有一家新店开在了以往每个店都倒闭的位置上-因为以往倒闭的店都竞争不过Colson’s.=>这家新店也会因为竞争不过Colson’s而倒闭。

提问：weaken结论的<=这家新店不会倒闭

前半句只是说打折商店互相竞争导致the discount stores in Goreville’s central shopping district 要关门（这里没有说不打折商店互相竞争会导致关门），而那些locations不会空着；

但是不懂前半句跟后半句的联系在哪里？

It is a tricky question.

There are several parts of the argument:

1) In the past 5 years, many stores closed because they fail to compete against Colson's, a non-discount store (probably a big one). Now, Spendless is also open, it is a discount store (porbabaly a big one too), so many discount stores are also expected to close in the next 5 years.

2) A new store will be opened whenever an old one is closed.

Its conclusion: 3) Accordingly, in the next 5 years, whenever one discount store is closed, another one will come up soon.
  

Now, if we want to weaken it, we have to prove that a new one will not come up.  B says it: The new ones that were opened were actually discount store, so they would not compete against Colson's. If in the future, any discount store is closed, a new one, discount or not, will not be opened because it can not avoid competition against both Spendless and Colson.

Hence, the correct answer is B.

Goreville’s central shopping district: SpendLess discount store =>other discount stores are expected to close within five years

Colson’s nondiscount store=>other nondiscount stores have been closed

SpendLess 和Colson’s是否都在Goreville’s central shopping district？

如果同类竞争要close，那么任何一家store-discount or nondiscount-都会关闭<=因为任何一家都竞争不过S&C,这样的话即使B中说a new store是discount store也还是会关门，因为它竞争不过S.

定位不同，自然不会竞争导致关门，意思是一个是打折商店，一个是不打折商店，两者自然不会竞争，也就不会关门，从而削弱了【结论 that 所有的商店都会因为竞争不过C而关门】

(B)

Increasingly, the stores that have opened in the central shopping district since Colson’s opened have been discount stores. (From the argument, we know that the discount stores in Goreville’s central shopping district are SpendLess's neibours so that the situation for SpendLess is different to Colson's).