千锤百炼的英文：
to undergo severe training and hammering; to be thoroughly tempered; to be well-seasoned; to be much steeled

参考例句：

Well-experienced;steeled and tempered;has gone through fire and water
千锤百炼

Severe training and hammering
千锤百炼

undergo是什么意思：
v. 经历，经受，遭受

To undergo or cause to undergo necrosis.
坏死引起坏的和使发生坏死

To subject to or undergo hydrolysis.
使分解受水解作用的影响或进行水解作用

The system undergoes no acceleration.
该体系不承受加速度作用。

severe是什么意思：
adj. 严重的；严厉的；严格的；严峻的；严肃的，纯洁的

Rape several women or have sexual relations with several girls
强奸妇女、奸淫幼女多人的

This assumption is false in several ways.
这种推断是错误的，错在了多个方面。

It comes with several inbuilt features.
他有很多固定的特征。

training是什么意思：
n. 训练；培训

the tail of a train
火车的尾部

explosive train
火药系

Is this dog trained?
这狗受过排便训练吗？