请教8老师：
父母回美证已经批了。现在他们要回国一段时间。请问8老师在国内呆大约（不到）5个月，持回美证回来会有问题吗？
-No problem.
在国内可以呆多久呢？
-As long as they come back before the AP expires, it will be fine.
如果在这期间绿卡申请批了，他们怎么回来呢？需要把绿卡寄给他们吗？-Not have to.
还是可以还用回美证回来？-Yes. Just tell the IO at the port of entry that their I-485 has been approved during their travel in China. If they don't know English well, you may write a letter for them and they just present the letter to the IO when they enter US using AP. They may also provide a copy of the I-485 approval notice or receipt (not required, but it is helpful).
