do you eat fast food? --Twice a week.A. How longB. How soonC. How oftenD. How far

问题补充：

--do you eat fast food?

--Twice a week.

A. How long

B. How soon

C. How often

D. How far

答案：

A. How long

B. How soon

(答案→)C. How often

D. How far

解析：考查情景交际。句意：--你多久吃一次快餐？--一周（吃）两次。how long对时间长短提问，与完成时连用；how soon多久以后，与将来时连用；how far对距离提问；根据答语可知，问的是频率，对频率提问，用how often。故选C。