They'll be back well before dark.

他们会在天黑以前回来。

《柯林斯英汉双解大词典》

The surface must be well prepared before you start to paint.

一定要把表面打磨好再开始粉刷。

《牛津词典》

Well before a championship, sports scientists and coaches start to prepare the athlete by developing a 'competition model', based on what they expect will be the winning times.

早在冠军赛之前，体育科学家和教练就开始建立“竞赛模型”来为运动员备赛，这种模型是基于他们对胜利时刻的期望。

youdao

Preliminary phase one tests of this new type of flu vaccine have already started in humans, but in an interview, Nabel said that even if all goes well, it will still be years before a universal flu vaccine is widely available.

VOA: standard.2010.07.21

Well the power points will be available before, say for this lecture it will be before so that you can use them in class.

幻灯片其实课前就能下载，这样你上课时就能用到。

哈佛公开课 - 幸福课课程节选

So supposed that I give you 16 elements to sort, well, following the logic before, the running time involved in sorting 16 elements is gonna be twice the running time 16 of sorting 8 elements, left half and right half plus 16 - and again, a little sanity check, 16 means-- just the merge steps, right?

现在要对16个元素进行排序，根据之前的逻辑，对16个元素排序,要花的时间是对8个元素排序所花时间的,2倍，分别用于左半部分和右半部分，再加上6,这里16是-,做合并的步数，对吗？

哈佛公开课 - 计算机科学课程节选

The best deals these days, it seems, must be snatched well before the clock strikes midnight on Thanksgiving.

FORBES: An Improbable Thanksgiving Day Rally In RIM Stock: Should You Now Feast Too?

They should be evacuated well before the general population.

CNN: Commentary: U.S. needs 'culture of preparedness'

We should expect new CBA agreements will be reached well before regular season schedules are cancelled or modified, as neither side wants to lose revenues, wages, or a public relations war from missed games.

FORBES: The 2010 Sports Business Year In Review