Archivist Constance Potter says genealogy can be addictive: once you start, it is hard to stop.

VOA: special.2010.06.28

But once you start publishing things in between covers, you actually have to decide what goes in and what goes out.

但一旦你开始把书籍加上封面出版，你就必须决定要出版哪些书。

耶鲁公开课 - 新约课程节选

In other words, once you start thinking about the evanescence of dominance, you're also thinking about literary history.

也就是说，每一种文学支配地位的消失，形成了文学史。

耶鲁公开课 - 文学理论导论课程节选

And once you start to see this, we realize, of course, our life is filled with this aspect.

一旦明白了这一点,我们就会发现,生活中处处都是这种体验

耶鲁公开课 - 死亡课程节选

So before, because of all these anti-business rhetoric, once you start intervene, s not just the question of the merit of the particular intervention, s the fact that nobody knows ll be intervening again.

所以之前，因为反商业言论，一旦你开始干预，问题就不仅仅在于，it’,某一桩干预事件的好处，而是没人能预料，it’,政府何时又会出手，when，you’

斯坦福公开课 - 经济学课程节选

So really, once we start writing more interesting programs, you would have to type out long annoying commands like that to just compile more sophisticated programs.

实际上，一旦我们开始写一些更复杂的程序时，你们可能要键入那样一些长的，讨厌的命令,来编译跟高级的程序。

哈佛公开课 - 计算机科学课程节选

It's all over the place, and as soon as I start to play it, at least once we get in to it, you'll say, "Oh, yeah, i've heard that."

我们经常会听到它,只要我一开始放,至少当我们听到主要部分,你们会说,原来这样啊,我以前听过

耶鲁公开课 - 聆听音乐课程节选

Then you get successively deeper, II through IV, slow, irregular, high amplitude delta waves, and then once you reach stage IV you start going up again, up through stage III and II.

然后睡得越来越深，从第二到第四阶段，慢，不规则，高振幅的δ波，等你到达第四阶段，你又开始返回，第三阶段和第二阶段。

耶鲁公开课 - 心理学导论课程节选

What you'll actually find in terms of asking your TAs about the Lewis structure rules is that sometimes they won't be as good at them as you are, and the reason is once you've drawn enough of these structures, you start to get a lot of chemical intuition about it just looks wrong to you if it's wrong.

其实如果大家去问助教,路易斯结构的规则是什么的话,你会发现他们有时候可能并不比你们记得更清楚，因为一旦你画过足够多的路易斯结构，你就会开始获得很多化学直觉,如果它是错的，那么对你来说它看起来就是错的。

麻省理工公开课 - 化学原理课程节选

Now, once you start thinking these thoughts, there's no need to restrict yourself to emotions.

当你开始萌生这些想法时,你会发现,不止情绪如此

耶鲁公开课 - 死亡课程节选

Of course, once you start thinking of it this way, it's natural to talk this way across a variety of things that the computer may be trying to do.

当然,一旦你开始用这种思维方式思考,你就会很自然地把这种思维应用到,电脑可能想要做的其它事情上

耶鲁公开课 - 死亡课程节选

So, what we do at the start of the semester, and these are essentially training wheels we very quickly take off once you get more comfortable, we provide you with our own library.

那我们这学期初要做些什么呢？,经过一些必要的训练,让我们迅速褪去无知，变得更加充实，我们会提供自己的库。

哈佛公开课 - 计算机科学课程节选

But I think once you start looking for them,you find them everyplace.

而且一旦查看起来，其实无处不在。

耶鲁公开课 - 死亡课程节选

Alright, so maybe a little underwhelming and we saw already what this program is going to do but let's just go through this process once before we start doing more interesting things and then we'll come back and at least give you a hint of what some of these syntactic details are doing.

好吧，这个程序也许太平庸了，让人印象不够深刻,我们也知道这个程序是干嘛的,在我们开始更有意思的事情之前,让我们再来讨论一下整个过程后再回来,这些语法细节到底是在做什么呢？,先给你们一点小小的提示。

哈佛公开课 - 计算机科学课程节选

We don't always want to go and solve the Schrodinger equation, and in fact, once we start talking about molecules, I can imagine none of you, as much as you love math or physics, want to be trying to solve this Schrodinger equation in that case either. So, what Lewis structures allow us to do is over 90% of the time be correct in terms of figuring out what the electron configuration is.

我们并不想每次都去解薛定谔方程，而且实际上，一旦我们开始讨论分子，我可以想象,你们中没有一个人，不管你有多么热爱数学或物理，会想去解这种情况下的薛定谔方程,总之，路易斯结构能让我们,有超过，90%，的概率判断出正确的,电子排布。

麻省理工公开课 - 化学原理课程节选