—Listen! Helen is singing in the next room.—It _______ be Helen. She has gone to Beijing.[ ]A. can&#
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题目简介
—Listen! Helen is singing in the next room.—It _______ be Helen. She has gone to Beijing.[ ]A. can&#
题目详情
—It _______ be Helen. She has gone to Beijing.
[ ]
B. mustn't
C. may
D. should
答案