OG13，CR25，树皮制药的C选项OG的解释看不明白，求教~~

lionsue

25. A drug that is highly effective in treatingmany types of infection can, at present, be obtained only from the bark of theibora, a tree that is quite rare in the wild. It takes the bark of 5,000 treesto make one kilogram of the drug. It follows, therefore, that continuedproduction of the drug must inevitably lead to the ibora’s extinction.

Which of the following, if true, mostseriously weakens the argument above?

(A) The drug made from ibora bark is dispensed todoctors from a central authority.

(B) The drug made from ibora bark is expensive toproduce.

(C) The leaves of the ibora are used in a number ofmedical products.

(D) The ibora can be propagated from cuttings andgrown under cultivation.

(E) The ibora generally grows in largelyinaccessible places.

答案是D， 这个理解，很直接的削弱，不过对C的OG解释看不太懂。为了搞清OG 的思路就纠结着想看懂它对这个错误的选项到底想说什么。。。谢谢大家帮助解释哦~~

OG解释C：C Theexistence of uses for other parts of the tree opens the possibility that theibora-bark drug wouldcause no increase in destruction of trees other than what exists already. If this information wereprovided, it would weaken support for the conclusion. Since it is not provided,this option does not significantly weaken the argument.

主要是灰色部分不太清楚。

lionsue

up

HarrisZheng

就是说  树皮药不会在（would cause no）现在已有的破坏（what exists already）的基础上增加新的破坏（increase in destruction of trees）

lionsue

谢谢楼上，不过为什么----如果叶子也可以制药的话，树皮制药就不会在已有的破坏的基础上造成新的破坏呢？
如果叶子和树皮都制药，还是会造成树木灭绝的情况啊。

lionsue

lzy74755

C选项是无关项，文章说的是此种drug的原料之一是bark，文章的逻辑链是对bark的需求会导致ibora的灭绝，并没有提及leaf，你只要关心bark是否会导致ibora的灭绝即可，至于leaf是否会导致根本无所谓。

大尾巴婷

那么E选项呢，它长在不可去的地方，必定怎么用也灭不了啊