more questions re 回複：more information requested by USCIS for

Well, I was born in Guangzhou, however, my parents live in Shantou now, my birth place showed as Shantou somehow, I don't know how that happened. CAn I attached a letter to explain it and correct it since I put my birth place as Guangzhou, Guangdong on all the forms I have filed. Or simply just re do a notary, if that is the case, can we do it here in US, or it has to be done by the notary in CHina?