多项选择题
Which three of the following descriptions are true about the firewall modes? （）
A. Transparent mode is layer 2. B. Routed mode is layer 3. C. Routed mode has 1 IP address. D. Transparent mode has 1 IP address.
单项选择题 What is the traditional mode for a firewall?（）
多项选择题 What are two characteristics of GSS?（）
多项选择题 What are two characteristics of OER? （）
