---Mum could I go shopping with you?- Yes . But you have to finish your homework firs

问题补充：

---Mum, could I go shopping with you?

--- Yes, . But you have to finish your homework first.

A. you can

B. you could

C. you can’t

D. you couldn’t

答案：

(答案→)A. you can

B. you could

C. you can’t

D. you couldn’t

解析：句意：妈妈，我可以和您一起去购物吗？可以，但是你必须先完成你的作业。could在此处表示委婉的语气，与时态无关，所以回答时还是用can，故选A。