我已经不知道我们花了多少钱了。

I've ___lost ___track of how much we've spent.

我们玩得太开心了，以至于忘记了时间。

We were having so much fun that we ___lost ___track of time.

她搬走了，从那以后我就不知道她的情况了。

She moved away, and I've ___lost ___track of her since then.