我現在就可以工作了,還是要等卡拿到才可以。
-Technically you can work, but the employers normally will not allow you to work unless you show them the green card or EAD.
還是我可以用工卡工作?
-Yes before you get the GC or GC stamp.
還是我應該在護照上蓋章才可工作?
-Yes, it is better.
另外WELCOME LETTER 說三星期內寄卡,是就三星期,還是可能會遲些。
-may be sooner or later.