"We are not always going to be right. And I do not want everybody disappointed if we make a mistake here or there.

VOA: standard.2009.03.20

If you have a real gas and you write du is Cv dT and your path is not a constant volume path, then you are making a mistake. But for an ideal gas, you can always write this. And this turns out to be very useful to remember.

对于真实气体，如果其变化过程,不是恒容的，du=Cv*dT就不成立，但对于理想气体,这条规则永远成立,这一点非常有用，请记住。

麻省理工公开课 - 热力学与动力学课程节选

But at some point in the eighteenth century, the mask seemed informally to acquire an alternative title, Comus, and it's as Comus that all readers since have almost always referred to the mask -- and this, of course, is a mistake.

但在18世纪的某个时候，《面具》似乎还有一个不太正式的名，《Comus》,因为《Comus》，后来读者都将它代指《面具》了,当然这是一个错误。

耶鲁公开课 - 弥尔顿课程节选