请教各位：
我为国内的母亲申请移民， National Visa Center 给我来信说：
The document you submitted is not an original or certified copy of an original issued by the appropriate government authority. The document must be an original, or a certified copy of the original, bearing the original seal or stamp from the issuing authority. 是不是 非得要原件， 我记得以前用原件的复印件都可以的， 是不是现在不行了。 上面说 certified copy of the original, 我以为是复印件。 大家帮忙给我确认一下。 不胜感激