It not only does something, as we'll see, it also gets something and it has to hand it back to me.

它不仅要做好自己的本分工作，还要将获取到的值返还给我们。

哈佛公开课 - 计算机科学课程节选

And here, in an isothermal expansion, The bath is putting back the energy that the gas is expanding or using to expand, and so the energy is flowing back into the gas through the environment in the isothermal expansion.

而在等温膨胀中，恒温环境将气体膨胀对外做功,而损失的能量又返还回来，在等温膨胀中,能量从环境,流向系统。

麻省理工公开课 - 热力学与动力学课程节选