噘倒，父母綠卡收到半年了，現在來信說是發錯了

父母綠卡收到半年了，現在USCIS來信說是發錯了，還要出生證明。60天之內不給證明就撤回綠卡。
This letter shall serve as notice that it is the intention of the USCIS to revoke the Petition for Alien Relative (Form 130) filed by you in behalf of the beneficiary, on ....
It has now come to attention of this office that your petition was approved in error.

怎麽會有這種怪事！

去年申請130時，把93年國內做的出生公證給了，後來又按補充材料要求給了醫院證明，戶口本。。。天，還要什麽證明？

現在國內能補做 BIRTH CERTIFICATE？

高手們給出出主意，我該怎麽辦？還是把像類似這樣的出生公證給寄過去？
http://www.51ielts.com/dispuker.asp?num=25524

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