—Has Billy finished his homework today?—I have no idea.Heit this morning.A. would doB. was

问题补充：

—Has Billy finished his homework today?

—I have no idea.Heit this morning.

A. would do

B. was doing

C. has done

D. had done

答案：

A. would do

(答案→)B. was doing

C. has done

D. had done

解析：依据答语中的时间状语可推知，比利作业未完成。他今天上午一直在做。过去进行

时除表示某段时间内一直在进行的动作外，还可表示某时刻正在进行的动作。如：

I was reading a book when he came in.