让我们彻底把这件事搞清楚！

Let's get to the bottom of this matter ___once ___and ___for ___all!

现在我确信我的妻子已经彻底离开了我。

Now I was sure that my wife had left me ___once ___and ___for ___all.

我们必须一劳永逸地解决气候变化问题。

We must address the issue of climate change ___once ___and ___for ___all.