__是用来尽快熄灭电弧的，以避免电弧延迟电路断开，烧伤触点、破坏绝缘，引起电器爆炸

微处理器本身不是计算机，它是微型计算机的核心部件，又称它为CPU。它包括两个主要部分

In which Spanning-Tree states does a switch port learn MAC addresses？ (Select two)

A. Blocking
B. Listening
C. Forwarding
D. Learning
E. Relaying

There are 2 switches in the Ezonexam LAN, with no routers. Ports 1, 2 & 3 are assigned

A. Host 1 on VLAN 1 can ping Host 2 on VLAN 1
B. Host 1 on VLAN 1 can ping Host 4 on VLAN 2
C. Host 1 on VLAN 1 can not ping Host 2 on VLAN 1
D. Host 4 on VLAN 2 can not ping Host 1 on VLAN 1
E. Host 4 on VLAN 2 can ping Host 2 on VLAN 2

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

When you compare the differences between half-duplex and full-duplex Ethernet, which of the following characteristics are exclusive to half-duplex？ (Select two answer choices)

A. Half-duplex Ethernet operates in a shared collision domain.
B. Half-duplex Ethernet operates in an exclusive broadcast domain.
C. Half-duplex Ethernet has efficient throughput.
D. Half-duplex Ethernet has lower effective throughput.
E. Half-duplex Ethernet operates in an exclusive collision domain.

Which of the following are true of Ethernet technology？

A. Hosts use a logical ring topology.
B. Hosts use a logical bus topology
C. Hosts must wait for an electronic signal to transfer data.
D. Hosts are directly connected to a wiring concentrator called a MSAU.
E. None of the above

A Ezonexam Ethernet switch receives a unicast frame. with a destination MAC that is listed

A. The switch will forward the frame. to a specific port
B. The switch will forward the frame. to all ports except the port on which it was received
C. The switch will return a copy of the frame. out the source port
D. The switch will not forward unicast frames
E. The switch will remove the destination MAC from the switch table
F. None of the above.

VE1 is a switch in the Ezonexam network. Why will VE1 never learn the broadcast address？

A. Broadcast frames are never sent to switches
B. A broadcast frame. is never forwarded by a switch
C. Broadcasts only use network layer addressing
D. A broadcast address will never be the source address of a frame
E. Broadcast addresses use an incorrect format for the switching table
F. None of the above

A new trunk has been configured on a switch in the Ezonexam LAN. By default, which VLANs are allowed over this trunk link？

A. No VLANs
B. Only the VLANs that are specified when creating the trunk
C. Only VLANs 1-64
D. All VLANs
E. All VLAN's except VLAN 1
F. None of the above