Now, the problem, or one of the challenges with clinical trials of vaccines is that you have to enroll a lot of patients into clinical trials because only a few are going to get sick in any case, only 20 out of 100,000.

现在的问题是,这也是疫苗临床试验的挑战之一,临床试验必须包括足够多的病人,毕竟只有一小部分人会被传染,十万人里面只有二十人被传染

耶鲁公开课 - 生物医学工程探索课程节选

You get sick and then you die, suggesting that sleeping is good to keep you healthy.

而是慢慢地生病死去，这表明睡眠对保持健康非常重要。

耶鲁公开课 - 心理学导论课程节选

Because doing that allows me to explain why people get sick.

因为那样做我就可以解释人为什么会生病

耶鲁公开课 - 死亡课程节选