— did you stay in Hong Kong?　　 — About 20 days.A. How oftenB. How soonC. How longD. How fa

— did you stay in Hong Kong?　　 — About 20 days.
A. How often
B. How soon
C. How long
D. How far

A. How oftenB. How soon(答案→)C. How longD. How far解析：句意：你在香港待了多长时间？——大约20天。A. How often 多久一次，表示频率；B. How soon将要多久，表示将要多长时间；C. How long多长时间，对时间段提问；D. How far多远，对距离提问。根据About 20 days.可知这是对时间段提问，故用疑问词how long。故选C。

和我的回答一样，看来我也对了