【题目】 ________ the morning train, he would not have been late for the meeting.
A.Did he catch
B.should be catch
C.has he caught
D.Had he caught

【答案】D
【解析】句意：如果他赶上了早班火车，开会就不会迟到了。主句的谓语动词是would not have been ，说明与过去事实相反，从句则可以用if he had caught the morning train, 本句中含有had，所以不用if时，就变成了 Had he caught the morning train。所以选D。