题目内容
Someone is knocking at the door. It _______ my mother. It’s time for her to be back.
A. can be B. may not be
C. must be D. mustn’t be
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题目内容
Someone is knocking at the door. It _______ my mother. It’s time for her to be back.
A. can be B. may not be
C. must be D. mustn’t be