她一旦喜欢上一个人，就会不顾一切地去爱他。

Tā yídàn xǐhuān shàng yí gè rén, jiù huì bùgù yíqiè de qù ài tā.

When she loves someone, she will love him no matter the cost.

现在我年纪大了，一旦受伤了，就要很长时间才能康复。

Xiànzài wǒ niánjì dà le, yídàn shòushāng le, jiù yào hěn cháng shíjiān cái néng kāngfù.

I'm old now, if I am injured it will take a long time to recover.

你一旦错过了这次的比赛，就要等五年后才能再看了。

Nǐ yídàn cuòguò le zhè cì de bǐsài, jiù yào děng wǔ nián hòu cái néng zài kàn le.

If you miss this game, you will have to wait five years before you can see it again.