In very severe cases, it can even defile some common objects, and in those cases, the source of impurity might have to be isolated or excluded if necessary.

在一些非常严峻的情况中，它会玷污一些普通的事物，在这种时候，不洁之源,也许只能被孤立，严重的话需要驱逐。

耶鲁公开课 - 旧约导论课程节选

We're going to get a deep insight if it's a necessary truth about death that everyone dies alone.

如果这是对死亡来说必不可少的真理,那我们能得到一些深刻理解。

耶鲁公开课 - 死亡课程节选

A narrower array of foods is necessary for nutritional adequacy if people are eating meat.

如果是吃肉的人,只需要几种就足够营养了

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Don't put in extra bells and whistles if it's not necessary.

不必要的话不要放进去,多余的铃声和口哨声。

麻省理工公开课 - 固态化学导论课程节选

Very difficult problems, but in my judgement, all solvable if we generate the country in the kind of bipartizan political cooperation and political courage that will be necessary to fix them.

这些问题很不容易解决，但我认为,不是不能解决，只要我们,以这种两党制的合作形式治理国家,还要有治理它们的政治勇气。

普林斯顿公开课 - 国际座谈会课程节选

If people are on the verge of dying, perhaps it is necessary to overlook that injustice, but I think it's important to keep in mind that we're still committing injustice by taking people's belongings or assets.

如果人们在死亡边缘挣扎，也许忽视这样的不公平是必要的，但我认为即使这样，我们依然要铭记,我们的行为不公正,这是在占有他人的财物或资产。

耶鲁公开课 - 公正课程节选

we're looking for something that's true,necessary,interesting and, if not unique to death,at least not true of everything.

我们要寻找的是真实，必要，有趣的，而且就算不是死亡独有，也不能是普遍事实。

耶鲁公开课 - 死亡课程节选