请教8老师持绿卡回国问题。本人在国内照顾病重的父亲3个月,前天刚刚返回美国。 问题1,我是否必须在美居住6个月后才能再回国内? -Not have to, but if you will stay in China for a longer time or go forth and back between US and China, you had better apply for reentry permit.