多项选择题
In which Spanning-Tree states does a switch port learn MAC addresses?（）
A. Blocking B. Listening C. Forwarding D. Learning E. Relaying
单项选择题 In a switched LAN network, what is the Spanning-Tree algorithm used for?（）
单项选择题 What are the switch and bridge port characteristics of a layer two spanning-tree network that is fully converged?（）
多项选择题 Which of the following are spanning tree port states?（）
