1. [多选题]Ezonexam is migrating to a private IP addressing scheme. Which of the following describe the use of private IP addresses? (Choose two)
A. Addresses chosen by Ezonexam.com to communicate with the Internet.
B. Addresses that cannot be routed through the public Internet.
C. Addresses that can be routed through the public Internet.
D. A scheme to conserve public addresses.
E. Addresses licensed to enterprise or ISPs by an Internet registry organization.
2. [单选题]以下特殊区域中哪一个没有自动下发缺省路由（）
A. 末梢区域
B. 完全末梢区域
C. NSSA区域
D. 完全NSSA区域
3. [单选题]介质工作在OSI的哪一层（）
A. 物理层
B. 数据链路层
C. 网络层
D. 传输层
