You can make multiple--you can put three or four-- the copy gets worse and worse each time, but you've got multiple copies.

你也可以复写多份，放上三四张复写纸-,不过越往下复印的效果会越差，但终归你还是有了多份副本。

耶鲁公开课 - 金融市场课程节选

You can't have just one copy; you have to have multiple copies.

你不是只有一份副本就够了;,你得有很多份才行。

耶鲁公开课 - 金融市场课程节选