And people give presentations and this is a photo of someone giving a presentation in a positive psychology summit.

被邀请进行讲座，这是一位学生,在积极心理学峰会上作讲座的照片。

哈佛公开课 - 幸福课课程节选

This is a photo by another American photographer, Walker Evans, a photo of Brooklyn Bridge. You recognize it.

这是美国摄影家沃克埃文斯拍摄的一张照片，你们可以看出，是拍的布鲁克林大桥。

耶鲁公开课 - 现代诗歌课程节选