This is Paris. It wouldn't have to be Paris.

这里是巴黎，也不一定非要是巴黎。

耶鲁公开课 - 文学理论导论课程节选

Oh, but I have a couple days. I don't have to do it right now."

哦，但是还有几天。我不一定非要现在做。

主修古典文学 - SpeakingMax英语口语达人

As we'll see in section today, a vaccine does not have to be totally perfect in order to prevent transmission of a disease, because when a disease enters a community its spread from one person to another.

有如我们今天看到的,疫苗不一定非要,绝对完美地阻止疾病的传播,因为当疾病侵入一个社区后,会在人群间传播

耶鲁公开课 - 生物医学工程探索课程节选

> So this tune made by one of our former students; but it doesn't have to be something written in Scratch, it doesn't have to be a game or animation it can simply be an incredibly, wonderfully way to spend time.

这段是由以前的学生制作的;,不一定非要用Scratch编写，也不一定必须是个游戏或动画,它只不过是用来打发时间的，一个好办法。

哈佛公开课 - 计算机科学课程节选