问题补充:
—Hurry up, Mum. The lights are turned on. Dad has been back.
—It be him. He has gone to Shanghai.
A. must
B. can’t
C. mustn’t
D. may
答案:
A. must
(答案→)B. can’t
C. mustn’t
D. may
解析:must必须,一定;can’t不能;mustn’t禁止;may可以。句意:快点,妈妈。灯已经亮了。爸爸回来了。——不可能是他。他已经去了上海。结合语境可知选B。