单项选择题 为了查看Quidway路由器搭建的帧中继网络的封装类型，应启用什么命令？（）

单项选择题 Refer to the exhibit. What does the (*) represent in the output?（）

单项选择题 A network interface port has collision detection and carrier sensing enabled on a shared twisted pair network. From this statement, what is known about the network interface port（）。