Question

-- Look at the boy running on the ground. Is it David?
-- It _______ be him. I saw him go to the teacher’s office just now.

A．might

B．could

C．can’t

D．mustn’t

Answer 1

C

本题的含义是我看见他去了老师的办公室，所以在操场上跑步的男孩不可能是戴维，故本题填不可能的单词can’t，故本题选C。