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。