单项选择题


听下面5段对话或独白。每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。听每段对话或独白前,你将有5秒钟的时间阅读各个小题;听完后,各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
How often should the bus come to their stop

A. Every twenty minutes.
B. Every half an hour.
C. Once a day.