Question

We ________ for her because she never came．

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

Answer 1

B
should not have done表示“過去不應該做而做了某事”，含有“后悔”、“責備”、“勸告”，“批評”之意。