If the person has not mastered the basic concept, the person must fail, must get four or less.

如果他没有掌握基本的概念，那就一定不能通过考试，只得十分之四或更少。

麻省理工公开课 - 固态化学导论课程节选

They might self-renew they might not, they have much more limited potential than before.

它们也许能自我更新,也许不能,它们比之前的干细胞潜能更少

耶鲁公开课 - 生物医学工程探索课程节选

These are going to be fairly common-sense definitions, but they're important, and when you get to a problem set, really nailing down what the system is, not more, nor less, in terms of the amount of stuff, that's part of the system, it's going to be often very crucial.

这些是,很常识性的定义，但是很重要，当你要解决问题时，务必要搞清楚系统是什么，它包含多少物质，不能多也不能少，这往往,是非常重要的。

麻省理工公开课 - 热力学与动力学课程节选