这是因为，它们，也只有它们，才能改变镜子里的反射。

This is because they, and only they, can change the reflection in the mirror.

youdao

老虎现在的领地只有它们原来的7%。

Tigers now occupy only 7% of their original range.

youdao

但是也许您不知道，并不是只有它们三个。

But lest you be unaware, they aren't the only three.

youdao

if we're actually thinking about electron configuration and we look at lithium, sodium and potassium, these all have one valence electron.

让我们来想一想,锂，钠，钾的电子排布，它们都只有一个价电子。

麻省理工公开课 - 化学原理课程节选

And that's what you want because the electron repulsion is only felt when you are in really, really close.

而那就是你想要的,因为电子间的斥力只有当它们,离得非常非常近时才能感觉得到。

麻省理工公开课 - 固态化学导论课程节选

Holy things only exist because of safeguards, rules that keep them separate, that demarcate them.

神圣的事物只有在保护措施，规定，存在的时候才会存在，它们被和世俗区别开来。

耶鲁公开课 - 旧约导论课程节选