回複：多次往返五/十年有效的B1/B2美國簽證

Of course. That is why the visa is called five year or ten year multi entry visa. However, you cannot work. And you normally cannot stay in the US for longer than six months. Before the expiration date of six months, you either must file for extension or you must leave. You can of course come back using the same visa, but you would not know how long you are able to stay this time. The length of time will be decided at the port of entry. They can let you stay for another several months, but they can also reject your entry. It is not guarenteed.