The answer is--this goes way back-- it's an old tradition and they used to have to do this by hand.

答案要追溯到很久之前,这是个古老的传统,他们过去用手工计算

耶鲁公开课 - 金融市场课程节选

Once we sort of settle into this vocabulary, and once we get used to this clearly unquestioningly scientific perspective, why on earth do we need pseudo-statement or fiction at all?

一旦我们习惯了这种用语，一旦我们习惯了,这种科学视角，我们为什么还需要伪陈述和虚构呢？

耶鲁公开课 - 文学理论导论课程节选

So what this means, if you used to have two children and now you have four, how do you provide for the extra two?

比如一家过去有两个孩子,现在多了两个,多了两张嘴,怎么办呢

耶鲁公开课 - 古希腊历史简介课程节选