回复：永久绿卡和临时绿卡physically有什么区别吗? 谢谢回答

As I know, the temporary GC can be take back if the holder changes his decision. For example, if an alien invests a money to establish a company, and he must hire a certain citizens and he could not withdraw his money within a certain time, such as two years; otherwise, his GC will be take back. However, permanent GC has not the problem.