[求助] og cr 68

meimei5656

68. 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 tree 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.

key: D

看了og得解释，我能明白为什么选D.

但是不能完全信服og对于E得解释：if the ibroa is largely inacessable, this bears on the question whether production of the drug could continue, not on what would happened if it did continue.

我的思路是：continued production of the drug不能lead to the ibora’s extinction.
因为The ibora generally grows in largely inaccessible places.即使 production of the drug到最后用完了acessable ibora, 因为还有一些他们触及不到。

这不是也weaken了吗？

盼xdjm,nn解疑，谢谢！

piqiuwawa

如果E所说的正确的话，那continued production of the drug都成问题了。这就是OG所说的意思。

但是，这是否定前提，你要找的答案是否定从前提到结论的这个推论。所以D是最佳答案。

meimei5656

首先谢谢楼主的回复，好心人呀！！！：）

但是我这个人脑筋又点死，我还是想不明白为什么一定要理会continued production of the drug这个结论中的条件呢？

我的思路是指要有其他原因存在，不会导致植物灭绝不就行了，不就weaken结论了？因为结论是片面的，没有全面考虑问题。

再详细解释一下好吗？谢谢：）

renprince

Let's understand it from another point.

Even such generally grows in largely inaccessible places, but as long as people need such medicine, the inaccessible will become accessible, right?

High deman leads to high price, high price lead people to take adventure.

So if they become accessible and they can't be grown manually, the plants will disappear eventually. right?

So D is the correct answer.