As with the passage on the falling of the leaves there's a kind of elegiac tone that works to undo, or at least to challenge, our theological certainty.

在描写落叶的段落里,有一种挽歌式的腔调，似乎要抹掉，至少是挑战神学上的确定性。

耶鲁公开课 - 弥尔顿课程节选

Are you among those more comfortable, have you taken any computer science, were you programming at the age of 10 but you'd actually like to learn a bit about things you don't yet know and challenge yourself with new content or are you somewhere in between?

你对电脑比较熟悉么，你上过计算机专业方面的课程吗？,你是不是10岁就会编程,来上课的目的只是为了学习未知的知识,或者用新知识来挑战战自我？,还是二者兼有？

哈佛公开课 - 计算机科学课程节选

For you or for me, it is not a challenge to walk around these cubes, or the audience or somebody from different points of view and recognize that they are really the same person.

对于我们这样的人，换个角度绕场行走，围着某个观众或者其他人去走,会认识到他们是同一个人。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选