I happen to have an extra copy.

我正好有一份多余的复印件。

youdao

There is an extra copy.

有多余的一份。

《新英汉大辞典》

You've asked the right person. I happen to have an extra copy.

你算是问对人了，我碰巧多了一本。

youdao

But some people are born with an extra copy of the twenty-first chromosome.

VOA: special.2009.09.09

I could have done this in another way but I am going to just be extra deliberate so I make sure that this copy ends with back slash zero and voila, now, I have a copy.

我可以用另外一种方式来处理,我确保这个拷贝由反斜杠0结尾,那样，现在我得到了一个拷贝。

哈佛公开课 - 计算机科学课程节选

"No court has ever held that you're entitled to make one extra copy of a DVD, much less five, " Pulgram notes.

FORBES: Magazine Article

The 32GB and 64GB storage options aren't shockers given the extra space Windows and the bundled copy of Office 2013 Home and Student 2013 will demand, but there's a treat for long-haul users in the battery -- it's been upgraded from the 7, 000maH pack of the Note 10.1 to an ample 8, 200mAh unit.

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So readers there are getting something extra to tide them over until the next copy of TIME hits their mailboxes the week after next: our Young Japan report is a double issue in Japan, with additional stories on the subject.

CNN: ASIANOW - TIME Asia