—Tom, where is your father? — I'm not
问题:
— Tom, where is your father?
— I'm not sure. He ______ in his office. [ ]
A. is
B. may be
C. maybe
D. may
— Tom, where is your father?
— I'm not sure. He ______ in his office. [ ]
A. is
B. may be
C. maybe
D. may