"If mistakes were made we need to know who made them and why they were made,".

VOA: standard.2009.06.15

All of that means we need to explain why these folks do what they end up doing, and we have some hints, but of course we do not know with any certainty or any confidence.

综上所述,我们来想想为什么这些人,要背井离乡呢,我们有一些线索,但是我们并没有有力的证据

耶鲁公开课 - 古希腊历史简介课程节选

one important argument was,or really family of arguments was, you need to believe in souls in order to explain why bodies are animated, why people are rational,how they can have personalities, how they can be creative,and so forth.

一个或一系列很重要的说法就是，要相信灵魂的存在才能解释身体的活动，为什么人会有理性和人格，为什么有创造力，诸如此类。

耶鲁公开课 - 死亡课程节选

We'll talk about some chemistry today, what DNA molecules are like, why they have the behavior that they do, and you need to understand this in order to understand how you manipulate DNA.

今天我们会谈到一些化学结构,比如DNA分子的形态,它们为什么会以这种形态存在,你必须先掌握这些,才能理解如何操控DNA

耶鲁公开课 - 生物医学工程探索课程节选