Adults should try to get seven to eight hours of sleep a night.

VOA: special.2010.06.09

How many people here on average-- from the beginning of the semester until now get on average more than eight hours of sleep a night?

这里平均有多少人-,从开学到现在,平均每晚睡超过八小时的？

耶鲁公开课 - 心理学导论课程节选

How many people here on average-- from the beginning of the semester until now get on average more than eight hours of sleep a night?

这里平均有多少人-,从开学到现在,平均每晚睡超过八小时的？

耶鲁公开课 - 心理学导论课程节选