pain：n.(身体上的)疼痛；痛苦；苦恼；

gain：n.(尤指财富、重量的)增值，增加；

相关介绍

It's amazing what some people will do for gain.

有的人为一己之利而干出的事令人惊讶。

His books have gained in popularity in recent years.

近年来他的书越来越受欢迎。

The pain was almost more than he could bear.

这种痛苦几乎使他无法忍受。

It was several weeks before he was completely free of pain.

过了几星期他的疼痛才完全消除。