单项选择题
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?（）
单项选择题 When a non-root user connects to a JUNOS platform and enters a username and password, the user is immediately placed at which level?（）
单项选择题 Which statement is true about the internal link between the Routing Engine and the Packet-Forwarding Engine?（）