謝謝8老師。讓我看到希望。
想知道從去美國領事館，放棄自己的綠卡，申請B2簽證，到最後進入美國，要多長時間？
-They can give up the green card and then apply for the B2 visa in the same day. The following website is for the green card abandonment:
http://guangzhou.usembassy-china.org.cn/abandonment-of-status.html
You can find such information in the website of any US Consulate in China.
Also more information:
http://www.immihelp.com/greencard/abandonment-greencard.html
因為曾經移民過，再申請非移民B2簽證，有多大把握能申請下來？
-Should be fine as long as they show they have no immigration intent in this trip.
多謝！！！
