问题
选择题
—____ do you clean your room?
—Every two days.
A．How soon
B．How long
C．How much
D．How often
答案
答案：D
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