问题补充：
You can certainly leave the classroom as soon as your homework.
A. has done
B. has been done
C. will be done
D. will have been done
答案：
A. has done
(答案→)B. has been done
C. will be done
D. will have been done
解析：在时间状语从句中可以用现在完成时表示将来，强调从句的动作发生在主句谓语所表示动作之前。
