Of no return

无路可退

Return n.归还；返回；（收益)回报；申报

例句：

I'mafraid I have to insist on the return of my books at once.

对不起,我要求你立即归还我的书。

The hopeof his safe return diminished as time passed by.

随着时间的推移,他平安返回的希望越来越渺茫。

The damage is done

伤痛已造就

Done adj.完成了的；煮熟的；对的；合乎礼仪的；累坏的

例句：

I amdone with the book.

这本书我看完了。

I'm not particular how you do it as long as it gets done.

只要把它完成了，你怎么做我并不计较。