单项选择题 Refer to the exhibit. Why has this switch not been elected the root bridge for VLAN1?（）

单项选择题 Why will a switch never learn a broadcast address?（）

单项选择题 Refer to the exhibit. Given the output shown from this Cisco Catalyst 2950, what is the most likely reason that interface FastEthernet 0/10 is not the root port for VLAN 2?（）