What people did is they said let's define a unit of energy that represents a unit charge accelerated across a unit potential difference, and let's call that the electron volt.

前人们所做的就是他们说让我们确定,一个能量单位用来代表一单位电荷,加速穿过形成的一单位电势差，我们叫它电子伏特。

麻省理工公开课 - 固态化学导论课程节选

So, what we're going to define is just let's just capture 90% of that electron density.

所以，我们所定义的,只包括百分之九十的电子密度。

麻省理工公开课 - 化学原理课程节选

So here, let's combine these to define a new quantity.

我们把这些结合起来组成新的物理量。

麻省理工公开课 - 热力学与动力学课程节选

Mr Clinton has yet to rally popular support for freer trade, let alone define America's agenda.

ECONOMIST: The risks to free trade

Let's create a real brand, define a space, understand who we are programming for.

ENGADGET

But the president's critics say that, once again, he has let Democrats in Congress define an issue in such a way that it makes the administration's job of winning the public's trust more difficult.

ECONOMIST: The row over bonuses