我幫我在中國的弟弟全家三人申請了綠卡, 已經批準。他們赴美的簽證已經辦好, 可在半年內來美國拿綠卡。可是我弟弟因工作原因不能在半年內來美國, 否則在中國的好工作就要丟掉。我弟媳婦和孩子可以來美國。請問如何能讓我弟弟保持綠卡申請有效並且晚些時候來美國拿綠卡(半年或一年後)?
-Your brother has to enter US to become a green card holder, otherwise his wife and kid can not become green card holders. Then, all the immigration visa will be void after 6 months later.