---must I take this medicine every day?- Three times a day.A. How longB. How oftenC. Ho

问题补充：

---must I take this medicine every day?

--- Three times a day.

A. How long

B. How often

C. How far

D. How

答案：

A. How long

(答案→)B. How often

C. How far

D. How

解析：回答语是每天三次的意思，表示的是频率，对此提问用how often，故选B，how long对长度提问，how far对路程提问，how对方式提问。