问题补充：
--- do you go hiking?
--- Once a week.
A. How many times
B. How often
C. How long
D. How soon
答案：
A. How many times
(答案→)B. How often
C. How long
D. How soon
解析：How many times多少次；How often多久一次；How long多长；How soon多久。根据下文，每周一次。可知上文提问的是频率，故选B，你多久去远足一次？
