Valvular disease is not uncommon in the world; we'll talk about that a little bit.

心脏瓣膜疾病在世界上是一种常见的疾病,我们会讲到一些相关的内容

耶鲁公开课 - 生物医学工程探索课程节选

And it turned out that another, not quite as deadly, but still very serious disease called syphilis was also common in this part of the world at that time.

现在已知另外一种疾病,它并不完全致命但也很严重,它叫梅毒,在那时的一些地方也很常见

耶鲁公开课 - 生物医学工程探索课程节选