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

I'd like to go there again someday.

我希望有机会再去一次。

享受冲浪 - SpeakingMax英语口语达人

For the first time"--this was, of course, the French aristocrat de Tocqueville "For the first time we have had the chance to examine the effect that slavery produces on a society.

第一次",这位托克维尔即是,法国的那位贵族德·托克维尔,"第一次我们有机会仔细观察,奴隶制对一个社会造成的影响

耶鲁公开课 - 美国内战与重建课程节选