Question

My sister met him at the Grand theatre yesterday afternoon,so he_______have attended your lecture.

A.couldn't B.needn't C.mustn't D.shouldn't

Answer 1

My sister met him at the Grand theatre yesterday afternoon,so he_______have attended your lecture
昨天下午我妹妹在大剧院碰见了他，因此他【肯定没有】参加你的讲座。

A couldn't 没有
B needn't 不需要
C mustn't 不准 禁止
D Shouldn't 不应该

这里根据句意可知，是(推测过去不可能发生的事情，用Couldn't have done)，请记住！选A

下面补充一点供你参考，和答题无关（这题标准答案肯定是A）：
但是，也有人提出了该题已不符合现代英语，尤其是美国英语的实际使用情况，应当改进。目前有充分的资料证明mustn't have done也可以用来表示“推测过去不可能发生某事”。例如：
1．His absence mustn't have been noticed．（CGEL）他的缺席一定没有人注意到。
2．Mr．Green mustn'thave received my letter，otherwise he would have replied before now．格林先生一定没有收到我的信，要不然他在这之前早就回信了。

【英语牛人团】牛人倾情奉献，您的满意使我们最大的追求，感谢您的采纳！

Answer 2

你好。答案是A
he COULDN'T have attended your lecture.
== It is impossible that he attended your lecture.

Answer 3

A
can't/ couldn't have done 根本不可能...
needn't have done 本没必要,,,,
must have done. 肯定已经.....(不要用mustn't have done.....)
shouldn't have done 本不该......

Answer 4

A,应该是他不可能会参加你的演讲，据前半句判断