— do you go skateboarding?- Twice a week.A. How soonB. How farC. How oftenD. How long

问题补充：

— do you go skateboarding? --- Twice a week.

A. How soon

B. How far

C. How often

D. How long

答案：

A. How soon

B. How far

(答案→)C. How often

D. How long

解析：句意：你多长时间踩一次滑板？一周两次。根据答语Twice a week.一周两次，可知提问的是频率，要用how often，故选C。