1. [单选题]After working all night and successfully configuring a Cisco router for the Ezonexam 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?
A. Hardware failure in NVRAM prevents the router from loading the config
B. Startup-config in flash is corrupt and cannot be analyzed
C. Router configuration-register set to bypass startup configuration
D. Startup-config in NVRAM is corrupt and cannot be analyzed
E. None of the above
2. [单选题]查看路由表的命令是：()
A. show interface
B. show run
C. show ip route
D. show table
3. [单选题]通配符掩码和子网掩码之间的关系是（）。
A. 两者没有什么区别
B. 通配符掩码和子网掩码恰好相反
C. 一个是十进制的，另一个是十六进制(hexadecimal system)的
D. 两者都是自动生成的
