单项选择题
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
单项选择题 You have just purchased a brand new router and wish to have the router prompt you through the initial configuration commands. Which router mode does this describe?（）
单项选择题 After working on a router, some problems arise and you wish to view the commands that you recently entered. Which IOS command opens the history buffer and displays the most recently entered commands?（）
单项选择题 After logging into a router and typing in a few show commands, you press the up arrow key. What will this do?（）