It was a long time before the cleanup was finished.

过了好久才清理完毕。

youdao

I threw it on my brother's bed and looked at it for a long time before I put it on and went out, smiling a "thank you" to my mom.

我把它扔在哥哥的床上，看了好长时间，才把它穿上，然后走了出去，微笑着对妈妈说了声“谢谢”。

youdao

It was a long time before he came to.

过了好一阵他才缓过来。

《新英汉大辞典》

Some doctors work a long time in hospitals before they are fully trained in a specialty.

VOA: special.2009.06.02

It's still--they can make losses for a long time before they're in trouble, so presumably there won't be a problem, but in principle there could be and so that's the kind of issue that we have now.

在陷入困境之前的很长一段时间内,他们可以承受亏损,也可以假设不会有任何问题发生,但是原则上讲是有可能会出问题的,这就是我们面临的现状

耶鲁公开课 - 金融市场课程节选

I was going to say when you first start doing this, even people who have been doing it for a long time still go off on ten-minute daydreams before realizing that their minds were wondering.

我本想说第一次尝试时，但即便是修行多年的人,也会走神十分钟之久,方才意识到自己刚做了白日梦。

普林斯顿公开课 - 人性课程节选

It will be a long time before people feel truly bullish about the economy.

ECONOMIST: The economy

The patients we see can suffer for quite a long time before they come along.

BBC: With gynaecomastia the breast takes on a womanly shape

It will be a long time before Mexico has a justice system worthy of the name.

ECONOMIST: The long path towards justice