There's always, and I think this is nearly invariable -there's an element in Milton's similes that stands outside the framework of the basic comparison.

有一点是时常出现并且几乎不变的,-就是在弥尔顿的明喻中始终有一个元素,是从基本的对比框架中脱颖而出的。

耶鲁公开课 - 弥尔顿课程节选

There's one quantity that's going to come out the same, no matter who is looking at the vector.

但是也有一个量是始终不变的,不管是谁在观察这个矢量

耶鲁公开课 - 基础物理课程节选