---Michael do you go swimming?Twice a week.A. how manyB. how longC. how oftenD. how so

问题补充：

---Michael,do you go swimming?

--- Twice a week.

A. how many

B. how long

C. how often

D. how soon

答案：

A. how many

B. how long

(答案→)C. how often

D. how soon

解析：句意：---Michael，你多长时间去游泳一次？---一周两次。How many多少，修饰可数名词复数形式，对可数名词的数量提问；how long多长时间，一般对表示for+时间段提问；how often多长时间一次，对表示频率的副词如usually，often等和短语once a week一周一次，twice a month一个月两次等提问；how soon多久，对in + 时间段提问。故选C。