We'll be talking about the fact that this is an interval of a third; it spans three letter names a little bit later on.

我们以后会谈到,这其实是个三度音程,它跨越了三个音名

耶鲁公开课 - 聆听音乐课程节选

Essentially, what they are is it's a protein that spans the membrane of a cell.

本质上来说，它是一个横跨细胞膜的蛋白质。

麻省理工公开课 - 化学原理课程节选