1. [多选题]Which of the following statements correctly describe the differences between half-duplex and full-duplex Ethernet? (Select two answer choices.)
A. Full-duplex Ethernet uses CSMA/CD to prevent collisions.
B. Half-duplex Ethernet uses a loopback circuit to detect collisions.
C. A full-duplex Ethernet card allows 20Mbps for data transmission.
D. Full-duplex Ethernet makes use of two pairs of wires for data.
E. An Ethernet hub can operate both half and full duplex simultaneously.
2. [单选题]把指定端口添加到VLAN的命令是：()
A. vlan
B. vlan-member ship
C. vtp
D. switch port
3. [单选题]在地址转换中，()用来规定哪些数据包需要进行地址转换
A. 在线用户表
B. 访问控制列表
C. MAC地址表
D. 路由表
