问题补充:
do you go to the library.I usually go to the library twice a week.
A. How long
B. How often
C. How far
D. How many
答案:
A. How long
(答案→)B. How often
C. How far
D. How many
解析:句意:你多长时间去一次图书馆?通常一周两次。how long 多长时间,提问时间段;how often 多长时间一次,提问频率;how far多远 ,提问距离;how many多少,提问可数名词的数量,故选B。