The number you dailed is out of service 您呼叫的用户已停机 The number you dailed is power-off. 您呼叫的用户已停机 The number you dailed can not be connected. 您呼叫的用户无法接通 The number you dailed is busy now. 您呼叫的用户正在通话中 至于“掉线”,是不是正在通话的时候突然断了啊? 如果是这样的话,可以说:the line was just shuted.(线路刚刚断掉了.)