Which method loads the configuration which was active before your last commit?（）

单项选择题You enter configuration mode with the configure command. You need to abort the changes that you have made and start again with a fresh copy of the active configuration. Which command should you use?（）

A.rollback 0
B.load active
C.reset config
D.clear candidate config

单项选择题You are the top of the hierarchy in configuration mode. How would you save your configuration to a file on the router?（）

A.save configuration <filename>
B.save config <filename>
C.save <filename>
D.save run <filename>

单项选择题What information does the help topic command provide?（）

A.router’s version and serial number to help open a case with JTAC
B.software documentation describing features and configuration tasks within JUNOS
C.a brief description of commands and their default values
D.a verification of the current configuration on the router

单项选择题The auto-complete feature in the JUNOS CLI is triggered by which method?（）

A.space bar for both command and variable completion
B.space bar for command completion；tab key for variable completion
C.space bar for variable completion；tab key for command completion
D.tab key for variable and command completion；space bar for command completion

单项选择题In which mode are users allowed to configure the device, including interfaces, protocols, user access, and system hardware properties?（）

A.priviledged mode
B.configuration mode
C.monitoring mode
D.operational mode