母親有綠卡，回中國半年，最近因病住院動大手術，估計還得恢複半年才能來美，怎麽辦呢？
-As long as she can return to US within one year since she left US, it is fine for her to enter US using green card. If she can not return to US within one year due to illness, she needs to apply for the SB-1 visa in the US Consulate in Guangzhou to come back.
需要申請白皮書嗎？本人不在美國能申請嗎？
-She has to be in US physcially for the reentry permit application.
