On average,students using swear words were able to keep their hand in the water for about two minutes.

VOA: special.2009.08.18

On the other hand, temperature, volume and pressure are variables that are much easier in the lab to keep constant.

另一方面，温度，体积和压强,在实验室中比较容易保持恒定。

麻省理工公开课 - 热力学与动力学课程节选