If you want to borrow a football after school, your student here.
A. has to leave
B. mustleave
C. has to be left
D. mustbe left
网友回答
A. has to leave
B. mustleave
(答案→)C. has to be left
D. mustbe left
解析：句意：如果你想放学后借一只足球，你的学生必须被留在这。have to 客观上不得不，根据语境应选C。