You could run through a little loop to say keep trying until you get one. But one of the ways I could deal with it is what's shown here.

你可以运行一个小循环来不断地做,直到得到一个输入,但你应该做的是弄明白这里到底要干什么。

麻省理工公开课 - 计算机科学及编程导论课程节选

You have to pick and choose what you do according to some funds that you have.

你必须根据你有的一些资金来选择要干什么。

向往自由的生活 - SpeakingMax英语口语达人

What have you done to us, taking us out of Egypt?

你把我们带出埃及，是要干什么呢？

耶鲁公开课 - 旧约导论课程节选

it kind of definitely depends on what you want to do.

这当然要看你想干什么了。

在研究所工作 - SpeakingMax英语口语达人