It's good to have a vector pointing in the radial direction of length one.

所以引入这么一个模长为 1,方向沿圆心向外辐射的矢量作用很大

耶鲁公开课 - 基础物理课程节选

They say it's terrible because they'll have a kid and the kid'll grow up freaky and then the experimenter--it's an interview situation--says, "Well, no. Remember they're both using a lot of birth control."

他们说太糟糕了，他们会生小孩的,小孩长大会变怪胎的,然后向他们提问的实验者说，“不会，他们都做了避孕措施”

耶鲁公开课 - 心理学导论课程节选

One of the things you kind of speculate about, and wonder about, why did some cities send out lots of colonies, some cities send out only a few, and others none at all for quite a while.

也许你感到疑惑的一件事是,为什么有些母邦派出了大量移民,另一些只有一些移民,还有其他母邦在很长时间根本没向外移民呢

耶鲁公开课 - 古希腊历史简介课程节选

er is a vector at each point of length one pointing radially away from the center.

r 是一个模长恒为 1 的矢量,方向沿半径向外

耶鲁公开课 - 基础物理课程节选