问题补充:
— do you clean your room?
—Every two days.
A. How soon
B. How long
C. How much
D. How often
答案:
A. How soon
B. How long
C. How much
(答案→)D. How often
解析:考查疑问词:A. How soon多久一次,B. How long多长时间,C. How much多少, D. How often多久一次,根据答语的内容Every two days,可知答案为D,表示多久···一次。故选D