Question

There was an accident in the factory, but no one knew who was _________ of the trouble．

[　　]

A．

at the end of

B．

at the top of

C．

in the middle of

D．

at the bottom of

Answer 1

答案：D
解析：

题意是“工厂里出现了事故，到底谁是祸首，没有人知道。”at the bottom of表示某事的根源，起因，导火索。A项，在……末端；B项，在……的顶部；C项，在……中间。