请问，父母（70多）持GC，回国已经一年半了，现要回来，入关会有问题吗，需要准备什么文件，谢谢！
-Their green card has been void already if they do not have renetry permit. Unless there was something preventing them to return to US in time such as serious illness, they may just abandon the green card and then apply for the B2 visa at the same time in any one of the US Consulates in China.
