In American history our reform crusades have usually had to do with one of several objects or purposes or problems.

在美国历史上我们为理想而进行的改革,通常与如下几个目的,或意图,或者问题之一有关联

耶鲁公开课 - 美国内战与重建课程节选

So you'll notice that I'm just going to put in numbers here and then the negative of the number and the numbers are roughly like this: . So the numbers are , , , , and .

你们会注意到我会先写一个正数,然后再写出它的相反数,收益大概如下,分别为,和

耶鲁公开课 - 博弈论课程节选