----Who swept the classroom?-I.A. doB. didC. sweptD. was

问题补充：

----Who swept the classroom?

---- I.

A. do

B. did

C. swept

D. was

答案：

A. do

(答案→)B. did

C. swept

D. was

解析：考查对疑问句的回答。问句意思为谁扫得教室，swept为过去式，回答也应用过去式，为了避免重复用did代替swept the classroom，故选B。