-- do you go to visit your friends?--Twice a month . 　　A. How often　B. WhenC. What timeD.

问题补充：

-- do you go to visit your friends?

--Twice a month .

A. How often

B. When

C. What time

D. How many

答案：

(答案→)A. How often

B. When

C. What time

D. How many

解析：How often 是对频率的提问，经常用来询问多久一次