These are obvious, but just to put them in comparison with what you'll see in the middle.

这些挺明显的,但是好让你们能和,之后看到的一些图片做个比较

耶鲁公开课 - 欧洲文明课程节选

OK, well.I'll try to explain this, This is a picture that was taken about 50 years ago.

好吧，我试着来解释一下，这张图片大概是50年前拍的。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

Well, let me turn from pictures to text.

好吧，我们从图片转向文本吧。

耶鲁公开课 - 现代诗歌课程节选