Over here in the lower left corner, we have elements that as a group have very low values of average valence electron energy.

在底层的左侧角落，我们看到以组为单位的,价电子能较低的元素。

麻省理工公开课 - 固态化学导论课程节选

If you look at the up left corner, Gabriel was a student here in this class two years ago, when we came and presented on the program and he is currently a student in the MAPP program.

看左上角，两年前，Gabriel修读这门课，在我们来推广硕士课程时,现在他正在我校读硕。

哈佛公开课 - 幸福课课程节选