Maybe because I already have one.

可能是因为我已经有了一块了。

youdao

I already have one, thanks.

我已经有一个，谢谢。

youdao

I already have one.

我已经有一张了。

youdao

I am anticipating here, and we'll come back to this in other contexts: but it doesn't say "one thing led to another"; in my facetious reference to history as I have already given it to you.

讲得有点超前了，我们以后谈论别的文章时还会再说：,但是结构主义不会说，一件事引起了另一件事;,就像我之前开玩笑般地指到历史一样。

耶鲁公开课 - 文学理论导论课程节选

If you do not already have this knowledge, I suggest you read one of the many Options Primers available in print or online.

FORBES: Sailing into a Storm

If I sound quick to judge a music service I have yet to try, allow me to be clear about one thing: we already have more than enough music services.

FORBES: Is Research in Motion's BBM Music Service a Sign of the Company's Demise?

Besides, I already have four personal email accounts, and will be getting one for work any day now.

FORBES: How Google Turned Me Into My (Dead) Mom