Why we need air ticket and boarding card as evidence,

来源: 于 2007-08-14 14:57:04 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次
万年绿,

Thanks for the two articles, I just submitted the I-485.
I haven't got the point. I can not understand that 机票和登记牌就是离境的铁证.

Why we need air ticket and boarding card,for what?
Thanks for your advice