新东方section 16-1

1. The chanterelle, a type of wild mushroom, grows

   beneath host trees such as the Douglas fir, which

   provide it with necessary sugars. The underground

   filaments of chanterelles, which extract the sugars,

   in turn provide nutrients and water for their hosts.

   Because of this mutually beneficial relationship,

   harvesting the chanterelles growing beneath a

   Douglas fir seriously endangers the tree.

   Which of the following, if true, casts the most doubt

   on the conclusion drawn above?

   (A) The number of wild mushrooms harvested has

       increased in recent years.

   (B) Chanterelles grow not only beneath Douglas firs

       but also beneath other host trees.

   (C) Many types of wild mushrooms are found only

       in forests and cannot easily be grown

       elsewhere.

   (D) The harvesting of wild mushrooms stimulates

       future growth of those mushrooms.

   (E) Young Douglas fir seedlings die without the

       nutrients and water provided by chanterelle

       filaments.

答案是D，可我觉得E更有道理啊，大家帮忙看看啊！谢谢了

2045977 jj,  我觉得是这样的。

结论是：因为蘑菇和Douglas fir的互惠关系，收获蘑菇会危及Douglas fir。

E中说的是小的Douglas fir秧苗在没有蘑菇提供的营养和水分情况下会死。E取非，如果小Douglas fir秧苗有蘑菇提供营养和水分，就不会死。 这是支持结论的。

D中说的是，收获蘑菇会刺激蘑菇的生长。--〉对Douglas fir 是有益的。所以是直接weaken了结论。

D中说的是，收获蘑菇会刺激蘑菇的生长。--〉对Douglas fir 是有益的。所以是直接weaken了结论。谢谢Sophie mm的回复，我明白了。我想，我应该把题目看地更仔细一点就好。