父母2019年10月持绿卡（当时持有绿卡已满一年）回国，2020年疫情爆发，没能如期返美（当时没有考虑超过一年回美，所以没有提前申请回美RE-ENTRY PERMIT），现在疫情好转计划返美，请问8老师这种情况该如何处理， 急问。
-Technically, their green card are void and they need to apply for SB-1 visa to return to US to reinstate their green card. If thye don't have SB-1 visa, sometimes the IO at the port of entry might make a compromise to let them enter US (not guarentee, depends on how lucky they are).
