需要通知移民局吗?
-No. As long as they come back to US before the AP expires, it will be fine. But if they have overstayed (illegal stay) in US for > 180 days before they filed I-485, they can not leave US even if they have AP.
回美国是不是不需要申请签证,
-No.
只要中国护照和这个combo card?
-Yes.