"There is no way we can monitor the activities of each juror twenty-four hours a day.

VOA: special.2009.08.31

We practice six days a week, usually, you know, three to four hours a day,

通常我们每周练习六天，你知道，每天三到四个小时，

赛艇项目很流行 - SpeakingMax英语口语达人

The robotic systems are designed to operate twenty-four hours a day.

VOA: special.2009.05.12

And that is a problem since there are only twenty-four hours in a day.

VOA: special.2010.06.04