问题
选择题
--- Listen! David is talking happily with his mother in the next room.
--- It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.
A.should
B.must
C.can’t
D.mustn’t
答案
答案:C
考查情景交际和情态动词。“听!大卫在隔壁正在高兴地和妈妈谈话。”“她不可能是他的妈妈,她妈妈作为一名志愿医生,已经去云南了。”情态动词可表推测。Should“应该”;must“一定”;can’t“不可能”;musn’t“”禁止不,表推测。故选C。