假设很长时间之前有一棵树。

So, let's think back some long time ago.

youdao

因为在浪费时间之前你可以太多次地重写你的清单。

There is only so many times you can rewrite a list before you are simply wasting time.

youdao

尽量在你的最后通牒时间之前一到两天完成你的论文定稿。

Aim to have your final paper ready a day or two before the deadline.

youdao

This is why he's continually placing the imaginative origin of the poem back to the very dawn of time, perhaps even back before if you can imagine such a time -- before the very dawn of time.

这就是为什么弥尔顿总是试图把想象中的这首诗的起源,推至时间开始的时候，甚至更早,-如果你们能想象这样一个时间--在时间开始之前。

耶鲁公开课 - 弥尔顿课程节选

I got from a person that I worked with for two and a half years before coming here.

我在来这儿之前和他一起工作了两年半的时间。

写推荐书的人 - SpeakingMax英语口语达人

Here's a, actually here it did take 25 years, but they did, they did eventually step on before we started drinking 7-Up.

这个过程，这个过程真的花了二十五年的时间，但是他们做到了，他们在我们喝七喜之前制止了加锂的行为。

麻省理工公开课 - 化学原理课程节选