If you knew only the third derivative of the function, you can have something quadratic in t without changing the outcome.

如果方程里有三阶导数,你就可以引入一个二次项,但是结果却不会变

耶鲁公开课 - 基础物理课程节选

Again, we have to ask ourselves, we have to start thinking of the question about what does this mean for doing something about changing the world's diet, changing the nation's diet, changing the world's diet?

让我们来问问自己,考虑一下这个问题,改变一个国家的饮食文化,改变这个世界的饮食,这意味着什么

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Let's say you want to see how something like cigarette smoking is changing in the population and the rates of cigarette smoking, and you want to look at people every five years from 1970 to 2000.

比如你想知道,人群中吸烟者的人数变化,和吸烟者的比例,在1970年至2000年每五年的情况

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选