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我爸爸有绿卡，还没有过期，但是他已经2年没来了，会怎么样呢，我得重新申请他呢，还是他自己附加文件？谢谢
-His green card has been void automatically. He needs to abandon the green card in the US Consulate in China, and then he can apply for B2 visa to come to US. If you want to sponsor his green card again, you can do it as the same way as you did before.
Read this link for green card abandonment (English version):
https://china.usembassy-china.org.cn/zh/visas/immigrant-visas/us-citizenship-immigration-services-uscis/abandonment-status-form-407/

or (Chinese version)
https://china.usembassy-china.org.cn/zh/visas-zh/immigrant-visas-zh/us-citizenship-and-immigration-services-uscis-2/abandonment-of-status-form-i-407/?_ga=2.192469930.1237401524.1548266295-500966409.1542662677