，通常居住在中國，每5、6個月來美國一趟，保持著綠卡。
2020年元旦來過之後，就因為疫情不怎麽出門了，這麽久沒來，現在還能來嗎？會不會在入關時被遣返，還是會沒收綠卡，以其他身份讓他進來？
-Techincally, the green card is void, so he cannot use it to enter US. But if he is lucky at the port of entry, the IO may allow him to enter US if the IO is not very strick, but it is very risky.
正確的解決方法是什麽，去美國駐華領事館辦理什麽文件嗎？
-He may try to apply for SB-1 visa to enter US to reinstall his green card if he has absolute reasons to convince the VO at the US Consulate, but it is extemely difficult to get teh SB-1 visa. Covid 19 alone is not a enough reason to get the SB-1 visa.
如果被取消綠卡，影響以後辦B1/B2簽證嗎？
-He may abandon the green card volunteerly, then apply for the B2 visa to visit US later.
