Unlike the case for energy like you've seen in lots and lots of disciplines, where you can arbitrarily set the zero in a way that makes it convenient for you.

通过无数的练习题,你们已经看到这和能量不同，对于能量我们可以任意确定,能量的零点。

麻省理工公开课 - 热力学与动力学课程节选

Maybe I will add this on as a problem you should do in your homework.

也许我会把这个作为,练习题加到你们的作业中去

耶鲁公开课 - 基础物理课程节选

The other thing I want to let you know is that instead of having a new problem-set that you'll be assigned this Friday, what we'll do instead is we'll give you some practice problems, and these will be just more of the same type of problems that you saw before but that's another chance to try them out more.

另外一件我想要告诉大家的是,这周五将不会像往常一样,给大家布置新的作业,而是给你们一些练习题，这些题目只是另一些跟原来同样类型的习题,你们应该都已经见过类似的,但这是尝试再次解决这类题目的机会。

麻省理工公开课 - 化学原理课程节选

I wanted to say one more thing because I realize that you have to-- your first problem set will cover this-- is to talk about the concept that applies probability theory to Economics.

我还想提一点,因为我意识到...,你们的练习题中会涉及到这个,概率论在经济学中的,应用的问题

耶鲁公开课 - 金融市场课程节选