请教8老师: 妈妈是美国永久居民，打算帮我在中国的离婚哥哥申请移民。 在递交I-130时，除了出生公证证明他们的母子关系外，还需要文件证明我哥哥的离婚状态（unmarried) 吗？
-No. By the way, your brother can not get married again before he gets the green card. Otherwise, the I-130 will be void. If he wants to get married again, your mother needs to become a US citizen first before he gets married, thus the I-130 can be upgraded.
