I'll finish talking about these examples at the beginning of lecture on Tuesday.

下次周二的课开头我把剩下的例子讲完

耶鲁公开课 - 生物医学工程探索课程节选

it's clear that you want to add a vector that looks like that, because then you go from the start of this to the finish of that, you end up at the same point and you get this invisible 0 vector.

显然应该给它加上这样一个矢量,因为从这个矢量的起点指向那个矢量的终点,最终指向的是同一个点,你就得到这个不可见的零矢量

耶鲁公开课 - 基础物理课程节选