1，我父母是10年前就離婚了，我現在給母親（未再婚）申請美國綠卡，需要他們的結婚公證嗎？
-Not need it for your mother. But if you sponsor your father's green card, you need it for your father (both 結婚公證 and 離婚公證).
2，我母親拿到綠卡之後，每年必須在美國住滿半年保持綠卡嗎？怎麽移民局網站上說每年住滿半年是入籍的要求？母親並不打算以後入籍。
-Your mother must have the intent to live in US permanently. Occasionally, she can stay in China for > 6 months < one year, but if she travel to China too often, her green card might be trouble.
請教這裏的老師和有經驗的同學，不勝感激！！！
