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

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

The expected life spans increased dramatically in the last couple of hundred years until now, for people that were born when you were born you can expect to live to be 80 years old, a doubling in life span, fairly dramatic.

从几百年前到现在,预期寿命显著增长了,你们同期出生的那批人,能够活到八十岁,预期寿命增长了一倍,令人印象深刻

耶鲁公开课 - 生物医学工程探索课程节选

How do these performers play such long spans of music without any notation?

这些演奏者是怎样演奏这么长的音乐的呢,在完全没有记谱的情况下

耶鲁公开课 - 聆听音乐课程节选