问题补充:
--- does she chat with friends on the Internet?
--- Once a week.
A. How long
B. How often
C. How many times
D. How much
答案:
A. How long
(答案→)B. How often
C. How many times
D. How much
解析:How long多长;How often多久一次;How many times多少次;How much多少钱。根据下文,每周一次。可知上文提问的是频率,故选B。