Darn it! I've lost my keys!

真见鬼，我的钥匙丢了！

《牛津词典》

Let's see if we can darn it.

让我们看看是否能为您修补一下。

youdao

Why marshmallows, darn it?

真讨厌，怎么是棉花糖？

youdao

The upside of it of course though is that's it's pretty darn easy to implement.

尽管实现起来,相当容易。

哈佛公开课 - 计算机科学课程节选

But, darn it, that can't be the right path to my number.

FORBES: Economics-Based Planning

And gosh darn it that someone is going to pay.

FORBES: Zynga: Well, That Didn't Take Long, Two Shareholder Suits

The fact is, gosh darn it, many Russians like him.

FORBES: Vladimir Putin: A Symptom of Russia's Greater Problems