And that may generalize again and it keeps going until you either get back to Adam and Eve, I guess. I don't think they were born in the US as far as I know, or you find somebody who satisfies that definition or you find that none of your parents actually are in that category.

降低到我的父亲或者母亲,是不是天生的美国公民呢,这个问题可以继续向下分解,你甚至可以追溯到亚当和夏娃的时候,据我所知它们并不是出生在美国的,或者你要么找到一个符合定义的人,要么发现你的父母都不满足条件。

麻省理工公开课 - 计算机科学及编程导论课程节选

Okay what else defines a food? Yes?

还有其他条件来定义食品吗

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Of course, they're all sorts of conditions under which a reaction could be wrong in the lab or outdoors or however, right. But this is the way we're going to define delta H of reaction.

当然，在实验室或室外,之类的环境中，在这些条件下,反应可能出错，但这是我们,要定义反应的△H的方法。

麻省理工公开课 - 热力学与动力学课程节选