By the way,

来源: 于 2015-06-05 20:36:58 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次
you can tell whether your green card is based on EB-2 or EB-3 from the green card category code on your green card. If the code is E21 or E26, the it is based on EB-2 I-140; and if the code is E32, E36 or E37, then it is based on EB-3 I-140.