我朋友去年離開美國回中國,她當時剛拿到綠卡不久,沒辦白皮書,現在有急事需回美,但離美時間已超過半年,請問這種在海關是否會遇上麻煩? -No problem at all as long as she comes back within one year after she left U.S. 有什麽辦法解決嗎?