I-485 RFE

I received a request for evidence (RFE) on I-485 application to adjust status. The USCIS is requesting a copy of marriage certificate and a copy of an original birth certificate along with an English translation, that is registered and recorded with the civil authorities that have jurisdiction over birth records.

However, I already submitted Notarized Marriage Certificate and Birth Certificate with translation included in I-485 application. Why they are still asking for the certificates? Do I need to sent another copy or I have to get new certificates from China?

Please advise. Thanks!