问题补充:
—How often does your sister surf the internet?
—About.
A. three time
B. three times
C. three time every day
D. three times a day
答案:
A. three time
B. three times
C. three time every day
(答案→)D. three times a day
解析:How often 多久一次,句意:你的姐姐多久上一次网? 大约一天三次。故选D。