回复：请教8老师和皮匠：有个小孩绿卡的问题。

我现在有两个问题：
1。儿子上高中时来美国，他现在的绿卡到时会有问题吗？

-If he stay in Canada for more than one year continuously, his green card will be invalid. It seems difficult for him to keep the green card. So, he may just give up it.

2。或者说会失去现在的绿卡身份，那么那时我再申请我儿子，会不会有问题？

-Fine.