— Could I ask you a rather difficult maths question?— Sure .A. pardon meB. go aheadC. good

问题补充：

— Could I ask you a rather difficult maths question?

— Sure,.

A. pardon me

B. go ahead

C. good idea

D. forget it

答案：

A. pardon me

(答案→)B. go ahead

C. good idea

D. forget it

解析：考查情景交际。“我能问你一个很难的数学题吗？”“当然，问吧。”A“请再说一次”；B“请（开始）吧”；C“好主意”；D“没关系”。故选B。