所以首先，你通常在学年的前半段写好它。

So, the first thing is, you normally write it during the first half of the academic year.

youdao

本周你会很忙，尤其是前半段。

You're busy this week -- especially the first half.

youdao

前半段，你不得不因为听众的哄堂大笑而暂停。

In the first half, you're pausing for so much laughter from your audience.

youdao

What makes the law surprising is that if I only gave you half the law, namely every body will remain at rest if it's not acted upon by a force, you will say, "That's fine. I accept that, because here's something, you leave it there, it doesn't move.

这条定律妙就妙在,如果只看定律的前半段,即,如果物体不受外力作用,将保持静止状态,你肯定会觉得,"这没什么,我能理解,因为你把一个物体放在那里,自己肯定不会动

耶鲁公开课 - 基础物理课程节选