问题补充：
--Excuse me, is it from here to the hospital?
--It’s not far, about 20 minutes’ walk.
A. How often
B. How long
C. How far
D. How much
答案：
A. How often
B. How long
(答案→)C. How far
D. How much
解析：
试题分析:句意：对不起，从这到医院多远？不远，步行大约20分钟。How often多久一次，How long多久， How far多久，How much多少。根据It’s not far, about 20 minutes’ walk不远，步行大约20分钟，可知问多远，故选C.
