单项选择题 You are a senior network administrator at TestKing, and while performing thepassword recovery procedure on your 2500 series Cisco router, you type in thefollowing command:o/r 0x2142What is the purpose of this command?（）

多项选择题 While working in setup mode, a configuration line is typed incorrectly. What should you do to exit setup mode, without executing or saving any of the mistakes you made?（）

单项选择题 After working all night and successfully configuring a Cisco router for the TestKing network you save your changes on the startup config, reboot the router, and go out for a cigarette. When you return, none of your changes are active and the router boots to the initial configuration mode! Which of the choices below indicates the source of your problem?（）