英语选择题解释详细的进~

问题描述:

英语选择题解释详细的进~
________who caused you to server dinner an hour later than usual?
A.was heB.did heC.had heD.was it he
选哪个?为什么?说详细点,谢谢~

选D
这是强调句型It was he who caused you to server dinner an hour later than usual.