A. don't have to do it B. needn't have done it
C. wouldn't do it D. mustn't have done it
參考答案:B. needn't have done it
(needn't have done sth:指过去本没必要做但却做了，属虚拟用法，）
刚才，你本没必要这么忙，看，还剩很多时间呢。
如：
You needn't have told him that.
你本没必要告诉他。
A. don't have to do it B. needn't have done it
C. wouldn't do it D. mustn't have done it
參考答案:B. needn't have done it
(needn't have done sth:指过去本没必要做但却做了，属虚拟用法，）
刚才，你本没必要这么忙，看，还剩很多时间呢。
如：
You needn't have told him that.
你本没必要告诉他。