回複：回複：急問皮匠等:給父母辦綠卡,他們的結婚證丟了,怎麽辦結婚公證

From what I know, if your notarized birth certificate has both your dad and your mom's names on it, they don't need the notarized marriage certificate.
-It is true. Because even if your parents can not prove their marrige, but you can prove they are truely your parents. So no matter whether they are still in marrige or not, both of them are qualifed for the green card application under your sponsor.