问题补充:
My sister met him at Ningbo Grand Theatre yesterday afternoon, so he your lecture.
A. couldn’t attend
B. mustn’t have attended
C. shouldn’t attend
D. couldn’t have attended
答案:
A. couldn’t attend
B. mustn’t have attended
C. shouldn’t attend
(答案→)D. couldn’t have attended
解析: 从上文可知,句子叙述的是已经发生过的事情,故用完成时态,mustn’t have done表示禁止的意思,故选D,以此他不可能参加过你的演讲。