急问各位老师：父母绿卡突然收到批准通知，可是家里有事定了机票下周就要回国。本来计划用AP，现在怎么办？因为approval notice 说有可能需要打指纹什么的。机票是下周回国，明年3月份回美国。
1） 如果依照原计划回中国，推迟到3月份打指纹，他们回美国时用什么文件，还用AP可以吗？还是拿这个approval notice？
-Bring the passport and the approval notice to the local USCIS Office to get the I-551 stamp (green card stamp), and use the stamp to travel.
2） 如果11月收到打指纹通知，改期到3月份没关系吧？
-You can ask reschedule, but you cannot expect a specific date for the new schedule which is decided by USCIS.
其实递交申请表的时候五月份打过指纹啊，还会再打一次吗？
-Probably no. The words on approval notice is standard for every case, so it does not mean your father needs to do it unless he receives appointment notice separately later.
3）收到这个approval notice 是不是意味着不用面试了？
-Right.
求各位老师帮助解答，多谢！！！
