does he take this medicine?---Twice a day.A. How longB. How oftenC. How soonD. How muc

问题补充：

--- does he take this medicine?

---Twice a day.

A. How long

B. How often

C. How soon

D. How much

答案：

A. How long

(答案→)B. How often

C. How soon

D. How much

解析：四个选项分别表示多长、多久一次、多久和多少钱。根据答语，一天两次。可知选B，他多久吃一次这种药？