1. [单选题]The Ezonexam LAN is upgrading all devices to operate in full duplex. Which statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet?
A. Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
B. Full-duplex Ethernet consists of a shared cable segment. Half-duplex Ethernet provides a point-to-point link
C. Full-duplex Ethernet can provide higher throughout than can half-duplex Ethernet of the same bandwidth
D. Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex ethernet uses a jam signal
E. None of the above
2. [单选题]通配符掩码和子网掩码之间的关系是（）。
A. 两者没有什么区别
B. 通配符掩码和子网掩码恰好相反
C. 一个是十进制的，另一个是十六进制(hexadecimal system)的
D. 两者都是自动生成的
