Question

【题目】--- 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

Answer 1

【答案】C

【解析】

试题分析：句意：--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。