—You used to play football ?A. do youB. don’t youC. didn’t youD. did you

问题补充：

—You used to play football, ?

A. do you

B. don’t you

C. didn’t you

D. did you

答案：

A. do you

B. don’t you

(答案→)C. didn’t you

D. did you

解析：句意：你过去常常踢足球，对吗？Used to do过去常常做某事，在反意疑问句中前肯后否，故选C。