问题补充:
— do you have an Art Festival in your school?
— Once a year.
A. How long
B. How often
C. How far
D. How soon
答案:
A. How long
(答案→)B. How often
C. How far
D. How soon
解析:
根据答语once a year可知问的是频度,how often多久一次符合题意,故选B。how long问的是时间或物体的长度;how far问的是距离;how soon问还过多久,都不对。