--You speak English so well. have you learned English?
--For 5 years.
A. How many
B. How long
C. How often
D. How far
网友回答
A. How many
(答案→)B. How long
C. How often
D. How far
解析：疑问词辨析。How many多少个； How long多长； How often 多久一次； How far多远。根据答语可知询问的是一段时间，故选how long。选B。