Jennifer Bemisderfer says this involves thinking about a product's whole lifetime: "When those products are at the end of their useful life, how are they going to be broken down?

VOA: special.2010.01.26

Actually, those guys would be useful, not so much, hardly at all during the scrum of the phalanx, but should one side be retreating.

尽管远程兵种的作用有限,尤其是双方混战时几乎形同虚设,但当一方撤退时,他们的作用就显现了

耶鲁公开课 - 古希腊历史简介课程节选

And so we'll talk about technologies like this, where they're at, what the scientific basis of it is, and how they might be useful.

我们将讨论这门技术会应用于哪些领域,它的科学原理是什么以及,如何使他们发挥作用

耶鲁公开课 - 生物医学工程探索课程节选

And when I'm starting to write lots of lines of code, you know, it's frankly kind of useful to be able to see more on the screen at once without having to scroll.

当我开始写很多行代码的时候，你们懂的，这明显是有用的，当你可以在屏幕上看到更多的代码,而不用滚动屏幕。

哈佛公开课 - 计算机科学课程节选

So if you learn how to look at films and if you are a real film buff, even bad movies will be useful, because they will give you things to develop your sensitivity toward the nature of film itself.

所以如果你们可以学会如何看电影,如果你们真的对电影了如指掌，即使是不好的电影也会很有用，因为,它会培养你对,电影本质的敏感程度。

麻省理工公开课 - 电影哲学课程节选