That's why there's a lot of emphasis on sharpening your teeth by doing this class of problems.

这就是为什么强调要通过解决这些问题,来提高你的能力

耶鲁公开课 - 基础物理课程节选

So, we are going to specialize to a very limited class of problems in the rest of this class.

在接下来的时间里,我们会专门研究,一类非常有限的问题

耶鲁公开课 - 基础物理课程节选