问题补充:
—Kate, do you know it is from here to the post office?
—About twenty minutes’ walk.
A. how long
B. how often
C. how far
D. how soon
答案:
A. how long
B. how often
(答案→)C. how far
D. how soon
解析:About twenty minutes’ walk意思是20分钟的路程,表示的是距离故用how far来提问。