It ultimately evaluates that line of code but just once the stuff inside the curly braces, but the semicolon on the end, essentially has the effect of this.

它最终执行了那行代码,但是只有一次，当那个东西在花括号里，分号放在后面，本质上影响了这个循环。

哈佛公开课 - 计算机科学课程节选

And then other people are really excited because it's a once-in-a-lifetime opportunity

而另外一些人真的很兴奋，因为这是一个一生只有一次的机会，

正准备奥运会 - SpeakingMax英语口语达人

A couple of hours, because typically there's just one battle; one side beats the other and that's the war for now.

几个小时,一般来说只有一次战斗,一方攻打另一方,这就是战争

耶鲁公开课 - 古希腊历史简介课程节选

A cohort study means you take the same group of people and follow them every five years for that period of time.

定群研究意味着你只有一组研究对象,然后在研究期间每五年进行一次记录数据

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

There we go. Now if I do this, an infinite number of times, we should get roughly 50/50, but now we have the ability to do things only once in awhile.

开始，如果我们，不停地按这个按钮，我们大致会有一半的机会听到猫叫，但是我们每次只有一次按按钮的机会。

哈佛公开课 - 计算机科学课程节选

> So now that might not have felt like the fastest algorithm but think about what you could have done with that algorithm in each iteration, much like the phonebook up front here, you literally split that problem in two because on each iteration roughly half of you were sitting down and then another half and then another half.

虽然这并不是最快的算法,但如果把这种算法每次迭代,就像刚才查电话簿一样，你便将这个问题一分为二了,因为每一次迭代后只有一半坐下来,以此类推。

哈佛公开课 - 计算机科学课程节选