Just don't add stuff that's not there.

只要记住不要无中生有乱加力

耶鲁公开课 - 基础物理课程节选

and kind of having to rebuild or add stuff, and then

有些需要重建，加点东西，然后

迷上网页设计 - SpeakingMax英语口语达人

The stuff that people tend to add sometimes is to keep drawing the 10 Newtons that's acting on that.

有人经常凭空添加的力,总是把这个 10 牛的力硬加在这个物体上

耶鲁公开课 - 基础物理课程节选

Now, I will add, before people write letters and stuff, this is the clean version.

在你们做笔记之前,我要告诉你们,我放的这个是和谐版的"玩旷课乐吧"

耶鲁公开课 - 心理学导论课程节选

The other two you know are stuff you can add, and you know where you're adding those things, because the particle has a head start.

另外两项是可加可不加的,而且你也知道这两项是怎么来的,因为质点运动是有起点的

耶鲁公开课 - 基础物理课程节选