首先,这个问题是针对成年人的。我们通常认为,只有每晚睡够8个小时,身体才会健康。可是,加利福尼亚大学的丹尼尔·克里普克教授进行的一项为期6年,涉及110万人的调查表明,每天晚上睡8个小时或者更多(或者少于4个小时) First, the problem is for adults. We usually think that our body will be healthy only if we sleep eight hours a night. However, a six-year survey of 1.1 million people conducted by Professor Daniel Kripke of the University of California showed that sleeping eight hours or more per night (or less than four hours)