1. [单选题]以下（）LSA类型是ASBR来宣告外部路由信息的。（）
A. 类型1
B. 类型2
C. 类型3
D. 类型4
E. 类型5
2. [单选题]PPP工作在OSI的哪一层（）
A. 物理层
B. 数据链路层
C. 网络层
D. 传输层
3. [单选题]An administrator issues the show ip interface s0/0 command and the output displays that interface Serial0/0 is up, line protocol is up.What does "line protocol is up" specifically indicate about the interface?
A. The cable is attached properly.
B. CDP has discovered the connected device.
C. Keepalives are being received on the interface.
D. A carrier detect signal has been received from the connected device.
E. IP is correctly configured on the interface.
4. [多选题]The LAN needs are expanding at the Ezonexam corporate office, which is quickly growing. You are instructed to enlarge the area covered by a single LAN segment on the Ezonexam network.Which of the following are layer 1 devices that you can use? (Choose all that apply.)
A. A switch
B. A router
C. A network adapter card
D. A hub
E. A repeater
5. [单选题]You have a class C network, and you need to design it for 5 usable subnets with each subnet handling a minimum of 18 hosts each. Which of the following network masks should you use?
A. 225.225.224.0.
B. 225.225.240.0.
C. 225.225.255.0.
D. 255.255.255.224
E. 225.225.255.240
