could have done 本可以做而没做,但有时也表推测
must have done 过去一定做了某事
should have done 本该做而没做
would have done 本要做而没做
因为前面有前提,字典不见了,用must就比较合适
could have done 本可以做而没做,但有时也表推测
must have done 过去一定做了某事
should have done 本该做而没做
would have done 本要做而没做
因为前面有前提,字典不见了,用must就比较合适