不管怎样，在生活中一定要有乐趣。

No matter what, make sure you are having fun in life.

youdao

人一定要有国家！

One must have countries!

youdao

为安全起见，我们登山一定要有同伴。

For safety, we should climb with a partner.

youdao

But remember that you do have recitation on Tuesday, so that could be very helpful with the problem-set, so be sure to go to recitation on Tuesday, and have a great long weekend.

记住，周二有习题课，这对做课后题很有帮助，所以周二一定要来上习题课，周末愉快！

麻省理工公开课 - 化学原理课程节选

It is a little bit difficult in the sense that to have gotten into Princeton, one almost certainly has had to know something about something. Right?

之所以比较困难是因为,一个人如果想要进入普林斯顿大学，他一定,对某个领域有一定了解？

普林斯顿公开课 - 人性课程节选

We assume that unless we're dealing with Scheherazade, it has to have an end, but at the same time we might well ask ourselves, why does it have a middle? What is the function of the middle with respect to a beginning and an end?

而且我们认定一定会有结尾，除非讲故事的是那个，《天方夜谭》中的苏丹新娘，但是我们要问自己了，为什么故事一定要有经过呢？,故事的经过对于开头结尾来说起到什么作用呢？

耶鲁公开课 - 文学理论导论课程节选