Question

We ______ for her because she never came.

1. A.
   mustn’t have waited
2. B.
   shouldn’t have waited
3. C.
   mustn’t wait
4. D.
   needn’t wait

Answer 1

B
should not have done表示“过去不应该做而做了某事”，含有“后悔”、“责备”、“劝告”，“批评”之意。