大全-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.

我觉得应该选e啊，可是答案是d

   harvesting the chanterelles growing beneath a

   Douglas fir seriously endangers the tree.，为什么mutually beneficial会endanger呢？

哦，我知道了

他因导致