请教一题蓝皮书上的语法题

hahaxiaoqishi

3.The Audubon Society and other conservation groups, concerned over what they have perceived to be the serious threatening of the environment as posed by the policies of the government, are preparing for a major political effort.
(A) have perceived to be the serious threatening of the environment as
(B) perceived as the serious threat to the environment as
(C) perceive being the serious threat to the environment
(D) are perceiving as the serious threatening of the environment（E）
(E) perceive as the serious threat to the environment

为什么是E，B错在什么地方？

tianskye

B加了as,意思就变了呀，还是as 。。。。 as。。。。。很怪呀

hanyichen

as....as 没有比较对象