I730到达美国后绿卡如何办理（需要多久）

Important: One year after legally being granted asylum or refugee status in the United States, the applicant may apply for a Green Card and eventually for United States Citizenship.
根据美国法律你要在美国合法呆满一年后，可以开始申请美国的绿卡并最终成为美国公民。