He knew he was done for in the exam.

他知道他考试完蛋了。

I didn't study for this exam, I'm done for.

这次考试没复习，我完蛋了。

If it rains, the picnic will be done for.

如果下雨，野餐就完蛋了。

He doesn't have an umbrella, his clothes are done for.

他没有伞，衣服完蛋了。

If he finds out, we will be done for.

如果他发现了，我们就完蛋了。

The computer broke down, and my work is done for.

电脑坏了，我的工作完蛋了。

The car broke down on the way, we're done for.

车子坏在半路上，我们完蛋了。

If you're not careful, your plan will be done for.

如果你不小心，你的计划就完蛋了。

If we don't leave quickly, we will be done for.

如果我们不赶快离开，我们就完蛋了。

Their business was done for because of the economic crisis.

他们的生意因为经济危机完蛋了。