Otherwise how will they know?

要不然他们怎么能知道呢？

youdao

How will they know there's a bug?

他们怎么知道那是一个bug呢？

youdao

How will they know when they are done?

当他们知道做完以后会怎么样吗？

youdao

We are worried because we do not know how long they will stay or how we will take care of them.

VOA: standard.2009.10.27

and they get to know you and maybe assess how good you will be in the lab, so I think,

了解你，评估你在实验室里怎么样，所以我觉得，

要考入大学 - SpeakingMax英语口语达人

And how will they know if it's working, or whether or not we need to go to a plan B?

WHITEHOUSE: Presidential Press Conference

If an advertiser places an ad in a newspaper through Google, how will they know that they're still reaching their intended audience?

NPR: Google Tries to Bridge Newspaper, Web Ad Contracts

How will they know when Mali is ready?

WSJ: Anne Jolis: Too Quiet on Mali's Southern Front