问题：
— Is Mr. Smith in his office now?
— No, he _____ there. I _____ him in the library a minute ago.
[ ]
A. may be, saw
B. can"t be, see
C. mustn"t be, see
D. can"t be, saw
— Is Mr. Smith in his office now?
— No, he _____ there. I _____ him in the library a minute ago.
B. can"t be, see
C. mustn"t be, see
D. can"t be, saw
— No, he _____ there. I _____ him in the library a minute ago.
[ ]
A. may be, sawB. can"t be, see
C. mustn"t be, see
D. can"t be, saw
参考答案：