--- do you go to the movies?
--- Once a week.
A. How long
B. How much
CHow soon
D. How often
网友回答
A. How long
B. How much
C. How soon
(答案→)D. How often
解析：考查疑问词：A. how long多长时间B. how much多少，C. how soon 多久D. how often多久一次，从答语Once a week，可知是问多久一次。句意：你多久看一次电影？--一周一次。选D。