If they do not give us a treat we can play a trick them.A. atB. onC. forD. to

问题补充：

If they do not give us a treat, we can play a trick them.

A. at

B. on

C. for

D. to

答案：

A. at

(答案→)B. on

C. for

D. to

解析：考查固定短语play a trick on 开……的玩笑。故选B。