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

We need to know not only what are the primitives, but how do we make things meaningful in that language.

我们不仅需要知道什么是基本类型，还要知道我们在那种语言中,怎样使其变得有意义。

麻省理工公开课 - 计算机科学及编程导论课程节选

and they do not know how to fix the tire.

而车上的人对此束手无策。

I can 课堂 - SpeakingMax英语口语达人

Doctors do not know exactly how the brain stimulation works to help patients with Parkinson's.

VOA: special.2009.02.03

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

"You do not know how bad that is going to be. There have been children who have died from the swine flu,".

VOA: standard.2009.12.18

Unless you tell them what to do they're not gonna know how to do it.

除非你告诉它要做什么,它自己是不知道做什么的。

哈佛公开课 - 计算机科学课程节选

Dr.Vallenas says many mothers are discouraged from breast-feeding because they do not know how to get their baby to latch on properly to the breast's nipple, or because they suffer pain and discomfort.

VOA: standard.2009.08.01

How do you know, not only that it didn't happen to you last night?

你怎么知道，只是昨晚没有发生？

耶鲁公开课 - 死亡课程节选

How do we know that they are not going to keep it all?" The United States and allies France and Russia have supported the IAEA draft deal with Iran as a means to alleviate concerns that Tehran is using its nuclear program to develop atomic weapons covertly.

VOA: standard.2009.10.28

You do need to know how to use it, but it's not about the details of, where do the semi-colons go in Python. All right?

你们确实需要知道怎么使用它，但是并不是具体细节，比如在Python中怎么写分号，好么？

麻省理工公开课 - 计算机科学及编程导论课程节选

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

I can change everything overnight; it does happen. I put that in for a reason because sometimes some of you have not taken a physics course and you don't know how to do well in physics and slowly you catch on and by the time it's Final exam you crack the code; you know how to do well.

我能一夜之间扭转乾坤,确实有过这样的例子,我这样做是因为,有时你们中有人可能以前没上过物理课,不知道怎样学好物理,但慢慢地你赶了上来,到期末考试的时候,你忽然灵光一闪,考起试来得心应手

耶鲁公开课 - 基础物理课程节选

N 2 So any chemist should be able to just look at n 2 and know that it's a triple bond, but that's not something that we've learned how did to do yet, so let's go ahead and start a new topic that's going to allow us to have some sort of sense of what the valence electron configuration, which includes whether something's a single or double or a triple bond can be figured out for any given molecule.

任何一个化学家都应该能够仅仅通过看到2,就知道它有一个三键,但是我们还没学习如何做到这点，因此下面我们就开始进入一个新的主题,它将使我们能够有一定的认识,对于价电子的排布情况，包括可以对任何一个给定分子中的键是单键双键,还是三键作出判断。

麻省理工公开课 - 化学原理课程节选

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

Not only is it inevitable that you're going to die; not only do some people live longer than others, you don't know how much more time you've got.

你会死去这不仅是不可避免;,不仅有些人活得比另一些人久，你也不知道自己还剩下多少时间。

耶鲁公开课 - 死亡课程节选