Because it's so important. And I should add and also under reversible work, where the external pressure is equal to the internal pressure.

而且我还要说应该在外部压强,和内部压强相等的,可逆过程中引入它。

麻省理工公开课 - 热力学与动力学课程节选

Whereas for fluorine, fluorine is smaller than f minus is the one that's the outer shell shown here.

而对于氟来说，氟原子更小,与外部壳层在这的负一价氟离子相比。

麻省理工公开课 - 化学原理课程节选

But beyond the extremes, additions or subtractions to our external circumstances make very little difference.

但在这些极端情况之外，增加或减少的外部环境,产生的区别很小。

哈佛公开课 - 幸福课课程节选

Now in Kaufman's view the similarities, therefore, between the Israelites and Ancient Near Eastern religion and cultures that everyone was so busily finding and celebrating, these were in the end similarities in form and external structure, appearance. They weren't essential similarities.

在考夫曼看来，人们苦苦寻找的,犹太与古近东宗教文化的相似点,只是在形式和外部结构上相同罢了,这些并不是必要的。

耶鲁公开课 - 旧约导论课程节选