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

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：考查固定搭配。How long问多久How often问频率，多久一次；；How far问多远；How问怎样。根据Three times a day应是问频率，所以选B。