Question

_____ is known to all is that effective measures should be taken to deal with the problem of the over-exploiting of our resources.

A．What

B．It

C．As

D．Which

Answer 1

A

試題分析：考查名詞性從句。分析題干結構“ is known to us all”是主語從句，從句中缺少主語，what 引導主語從句，在從句中作主語。如果選 it，需去掉 all 后的 is，如果選 as需去掉 is that。句意為“眾所周知，面對過度開發資源的問題，我們應該采取有效的措施。” as 作為關系代詞引導的非限制性定語從句位于主句之前時， It從句與主句之間要用逗號隔開。作為形式主語將 that 引導的主語從句后置時，that 常常不能省。選A。