我律师给我们的485准备说明上是这样说的: You must provide all copies of I-20. If lost or misplaced, please ask your previous university if they have copies. If they don't have copies, you must draft an explanation in Microsoft word indicating what kind of form are missing, valid dates, name of sponsoring institution, and why they are missing. Also include that you have made an attempt to locate the copies of those forms in the university's files. 可以试试问学校还有没有copy。很大的可能是还能找到的。 bless!!!