If I had been working, I would have quit.

就算我上了班，也会辞职。

youdao

I had been working at Google for about four years.

我在Google工作了近四年。

youdao

I was tired that day, because I had been working all day.

我那天累了，我干了一整天的活。

youdao

I had been working at a public Accounting firm for a couple of years.

我在一家会计事务所已经工作了几年。

为什么是会计学呢？ - SpeakingMax英语口语达人

At this point, I had been working on a book about Marley's life for several years.

NPR: Bob Marley's Music and Magic Endure

Luckily, in the last year or so I had been working almost exclusively on Google Docs while writing for work or school.

FORBES: Google Saving Your Personal Data Can Be A Blessing

That very morning I had been working on the same issue.

FORBES: Missing: Gen Y