大全693，答案E

(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) perceive as the serious threat to the environment

哪位可以把从句的正常顺序理一下？

they have pereived (the thing posed by the policies of the government) as the serious threat to the environment.这样整理对吗?

concerned over是什么意思？谢谢！

concern over 关注

they concern over what they perceive as the serious threat to the environment posed by the policies of the government

threat posed by the policies of the government

请问这里如果用完成时对吗？

concerned over what they have percieved as the serious trheat to the environment.