已经收到一张 green card 和 welcome notice. 可是我又收到一个 welcome notice 说我将收到
green card 在三个星期内。如果真的收到两张卡，我该怎么办？
-It is just USCIS' mistake to send you such second notice and you will never receive second GC. If you get it, both GCs are valid if there are the same information in the cards, just like you have two keys in your lock of your house.
