数字电视已经面市一段时间了。

Digital television has been around for some time now.

《牛津词典》

主席的职位已经空缺一段时间了。

The position of chairman has been vacant for some time.

《柯林斯英汉双解大词典》

他到达那所房子应该有一段时间了。

He ought to have reached the house some time ago.

《柯林斯英汉双解大词典》

So what I'm saying now is it took a long time for this to solidify. And one of the things we think made it solidify was the development of codices,a codex.

所以这花了很长一段时间,才得以统一，我们觉得,使它统一的是抄本的出现。

耶鲁公开课 - 新约课程节选

Yes. Most of our clients are people who have been living in an apartment or in a house for a while

好的。绝大多数委托人都是在公寓或者住所内居住有一段时间了，

我帮助过的人们 - SpeakingMax英语口语达人

I could have just done this, and the only reason I didn't here is just because now I look - at this, and now it's just getting confusing for me -- even for someone who's been programming for a while.

我本可以这样做，我之所以没有这样做是因为,现在我看着这个，它是我有点迷惑了-,甚至是对于某些已经写了一段时间程序的人来说。

哈佛公开课 - 计算机科学课程节选