And in lots of other situations, certainly if you look at any living biological system, including yourselves or your friends or any other one, it's certainly far from equilibrium.
And the equilibrium approximation where the system sets up a very fast equilibrium and you're allowed to use thermodynamics to help you out in solving the problem.
平衡近似是，系统建立起一个快速的平衡，你可以用热力学，帮你解决这个问题。
3
If the system is perturbed by some force and pushed in a new direction, it usually moves back toward equilibrium quickly.