请问一下，我收到的W-2里面，怎么有两个给state tax return的copy 啊

一份叫 XX state reference copy

另一份叫 XX state filing copy

两份下面都印了

Copy 2 to be filed with employee's state income tax return

难道是2份都要附上？还是附上filing copy，我自己留reference copy？

谢谢