So, you can imagine in certain circumstances there would be guys that old back there, but fundamentally it's between 20 and 45.

所以你能想象,在某些情况下,也会有老年人,但基本上是二十到四十五岁的

耶鲁公开课 - 古希腊历史简介课程节选

Fungi which don't often cause infections in people with healthy immune systems but can under some circumstances, and can be tremendous problems in patients that have weakened immune systems.

真菌在免疫系统健康的情况下通常,不引起感染,但在某些情况下也会感染,那就成了极大的问题,在免疫系统脆弱的病人体内

耶鲁公开课 - 生物医学工程探索课程节选