Let us say I want to sell my car but I do not know exactly how much it is worth.

VOA: special.2009.04.12

I don't know how many kids, generation after generation, get in trouble because they do not remember the following fact.

我不知道有多少孩子,一代又一代,因为没有记住下面的内容而遇到困难

耶鲁公开课 - 基础物理课程节选

But if you say, well, I don't know how to do this, I am not going to bother, don't grade the paper.

但是如果你说，好吧，我不知道怎么做这个，我想麻烦，别给试卷评分。

麻省理工公开课 - 固态化学导论课程节选

How could I answer the child? I do not know what it is any more than he.

VOA: special.2009.04.12

I mentioned previously that we do not know a lot about how the mechanical stimulation is being converted into chemical and electrical energy.

先前我曾说过,对于机械刺激到化学和电能的转换,我们还知之甚少。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

How old I do not know.

VOA: special.2010.07.10

same point Cartesian to have 1 representation for a point that supports different ways of getting information out, but has gathered within it, a method or a function for dealing with things like how do I know if it's the same point or not.

还有,这是一个比较极坐标的点,是否相同的不同的方法，但是这开始成了一个麻烦事儿了，我真正想要做的事情是,创建一个能支持不同的方式,输出已经收集的信息的点的表示。

麻省理工公开课 - 计算机科学及编程导论课程节选

I know that's not possible, but how do we reconcile this?

我知道这是不可能的，但到底如何达成协调？

普林斯顿公开课 - 人性课程节选

How do I know," Descartes said, "I'm not dreaming right now?"

我又如何能确定我现在不是在做梦呢"

耶鲁公开课 - 心理学导论课程节选

I think what makes a difference is not only do you, yourselves, know better how to play this game now, but you also know that everybody around you knows better how to play the game.

我觉得因为不仅你们自己,玩这个数字游戏玩得更好了,你们也了解到周围的人,也玩得更高了

耶鲁公开课 - 博弈论课程节选

And Descartes said, "How do I know I'm not crazy?

笛卡尔问道,"我如何才能确定我不是个疯子

耶鲁公开课 - 心理学导论课程节选

Well, one answer is because what I-- how I score on that test isn't going to tell you anything about me It's not going to relate to my grades It's not going to relate to how well I'm liked ? How do we know the SAT is useful?

一个原因是,我在那个测试中的得分,不会透露出任何我的信息,与我的学习成绩无关,也不会说明我有多受欢迎,我们怎么知道SAT有没有用？

耶鲁公开课 - 心理学导论课程节选