是我逻辑有问题？

rainygo

OG13-25：

A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.

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

(A) The drug made from ibora bark is dispensed to doctors from a central authority.
(B) The drug made from ibora bark is expensive to produce.
(C) The leaves of the ibora are used in a number of medical products.
(D) The ibora can be propagated from cuttings and grown under cultivation.
(E) The ibora generally grows in largely inaccessible places.

标准答案选D，我选的E。 我的理解是，原文是说ibora会灭绝，那么就找个不会让它灭绝的理由。 选项D我也能理解。 但是选项E说它生长在难以接近的地方，OG解释说“Difficulty of access to the trees could provide a disincentive to their harvesting—but we are not told that it would prevent their harvesting.”
1. 难以接近，所以无法收割，那么它就不会灭绝，那么E没错
2. 如果D对，那么ibora可以被种植，为什么还要费尽千辛万苦去个inaccessible的地方去收割呢？ 如果不去收割的话，那就不会灭绝啊。 所以如果D对的话，那么E应该也对呀。
是我思维有问题？

荒草

同学你想太多了
OG解释的很对, 不容易接触到的确对于使用他来说是不方便的, 但是并不能推出一定就不去使用这类植物. 也许虽然难以接触, 但为了制药还是都砍光了, 所以还是会灭绝. 没有起到weaken的作用.

至于你的第二条,我没看懂
D的意思是 1, 切断的地方可以继续生长, 2, 这种植物是可以种植培育的
你为什么要把D和E 联系起来考虑呢.

soulwangh

The first question：

It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.  
The premise of this argument is "It takes the bark of 5,000 trees to make one kilogram of the drug".
The conclusion of this argument is " That continued production of the drug must inevitably lead to the ibora's extinction follows."

Watch out "continued production of the drug". This sentence means that if we continue product the drug, then the tree will extinct.
The precondition is that we can product the drug no matter where the trees grow even if difficulty of access to the trees could provide a disincentive to their harvesting. The conclusion about the extinction of the tree is based on the validation of the precondition.

The second question:

In Gmat, the answer choice must be considered individually. Don't confuse it with DS problem.

rainygo

荒草 发表于 2013-11-1 15:52
同学你想太多了
OG解释的很对, 不容易接触到的确对于使用他来说是不方便的, 但是并不能推出一定就不去使用 ...

好吧，是我想太多