因父母10年前探亲签证拒签， 他们不想再去签证，母亲年纪80 岁， 特想看看我在美国的生活， 我就给老母办了移民签证，她从国内过来了两个星期了， 在等绿卡，一般多长时间能拿到绿卡？
-Normally she can receive the physical green card in about one month. But if she want to go back to China, she can leave any time even if before she gets the physical green card.
如果她想回国， 可不可以在未等到拿到绿卡之前回国，
-Yes, of course. She can return to US within one year even if she just her passport which has the green card stamp got at the port of entrywhen she entered US using the immigration visa.
我在这里收到绿卡后再寄给她？
-Of course yes and that will be good. But she can not stay in China for > one year unless she apply for the reentry permit. Otherwise, her green card will be invalid.
进入中国海关会有问题吗？
-Not at all.
实际上我并不知道以后母亲还会来吗，因年事以高，象我们这种情况， 最好怎么做？
-She had better apply for the reentry permit which can allow her to stay in China for > 1 year < 2 years continuously.
谢谢
