I'm going to give you a glass case and in the glass case is an entity with this as one kilogram, by definition.

我给你一个玻璃箱,箱子里放的东西刚好是 1 千克,这是根据定义的

耶鲁公开课 - 基础物理课程节选

The question was how many rabbits do you have at the end of a year? At the end of two years? At the end of more than that number of years, and so. We can do this with the following level definition. We're going to let pairs of 0, the number of pairs at month 0, actually it would not be it would be 1.

在下一个月末的时候让我们假设,这2只小兔子也有了后代,同样是一公一母,问题是一年后你会有多少只小兔子？,两年后呢？更多年后呢？,我们可以用接下来的等级说明来解释，在第0个月有0对兔子。

麻省理工公开课 - 计算机科学及编程导论课程节选

If we defined food differently: that it's something that nurtures the body, something found in nature, something that doesn't harm the environment-- there are a number of criteria one can apply to define a food-- then we might come up with a different definition than this, but this is the way the nutrition field generally looks at it.

如果我们给出不同的定义,滋养身体的物质,在自然界找到的物质,不会威胁到身体的物质,有很多标准可以拿出来定义食物,我们也许可以就此重新进行定义,但这就是营养学看待食物的方式

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选