But that's a little bit hard, we aren't all that good at seeing electrons with our eyes, so we need to think of a way to do this.

但那有一点困难，我们都不能通过眼睛看到电子，我们需要想一种方法去做到它。

麻省理工公开课 - 化学原理课程节选

It also is a good lesson in how difficult it is, and we'll talk about this in a subsequent class, to actually measure what people eat.

同样这能很好的说明,实际评价人们的饮食有多困难,我们下节课会讨论这个话题

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Last time we stopped, we talked about how difficult change is.

上次我们讲到改变有多么困难。

哈佛公开课 - 幸福课课程节选

We have a nice theoretical framework, but the application of the framework to the real data is hard and it ends up with politics underneath it all; that's just the real world.

我们有清晰的理论框架,但实际运用理论知识却困难重重,最终还是政治支配一切,这就是现实社会

耶鲁公开课 - 金融市场课程节选

instead of pursuing the questions of how exactly that theory should go, notice that if we had that theory ... we could still evaluate in principle-- whatever the practical difficulties might be-- in principle we could still evaluate rival lives.

我们不去研究,那种理论如何发挥作用，即便我们有那种理论,原则上我们仍然可以-,不管实际困难是什么-,原则上我们仍然可以评价其他生活。

耶鲁公开课 - 死亡课程节选