我母亲申请去年二月递的，现接到通知8月初面试。现在碰上国内家里有事，要考虑她何时来美呆多久。请教：
1、I-864担保，我是去年二月份随申请寄给移民局的。现在已超过十二个月。面试时是重填一份还是第一份即可？原件已寄给移民局，我只有复印件。面试时说要带原件，我担心现在邮寄回国来不及，扫描在国内打印可以吗？-Fine.
2、要求提供most tax return, 交NVC文件时2018还没有报税，交了前面三年tax transcript. 今年报税晚了，tax transcript没有，交1040税表复印件行为。-It is fine to provide the copy of I-1040 of 2018.
3、我打算准备雇主信和W2, 不邮寄回国，用扫描打印行吗？-Fine. But had better use color printer.
4、关于绿卡生效时间，是以按登陆美国算吗？-Yes.绿卡要求每年最少呆180天是怎么算的。如果我母亲8月初通过面试就来美，这个180天怎么算呢，她最早什么时候可以回国-She can leave US any time after she enters US. But she cannot stay in China for more than one year, and occasioanlly it is fine to stay there for > 6 months < then one year. The green card is for her to live in US permanently, not for her to use it as border-crossing card. So, she cannot travel between US and China too often.
5、面试后多久可以拿到护照、-I don't know. 移民签证日期是从面试日开始吗？- Depends on when it will be approved.
