第26题: [单项选择]局域网交换机的帧交换需要查询( )。 A. 端口号/MAC地址映射表 B. 端口号/IP地址映射表 C. 端口号/介质类型映射表 D. 端口号/套接字映射表 参考答案:A 答案解析:[解析] 局域网交换机是利用“端口/MAC地址映射表”进行帧交换的。交换机的“端口/MAC地址映射表”可以根据交换机的端口号及其连接的结点MAC地址建立对应关系。当结点间通过交换机传送帧时,交换机的控
第27题: [单项选择]{{B}}Questions 11 to 18 are based on the conversation you have just heard.{{/B}} A. They have to bargain on the sale. B. The TV set is usually on sale. C. They advertise to sell their TV set. D. They go to buy a TV set at a bargain price 参考答案:D 答案解析:[听力原文]
M:This TV set is getting worse and worse.Now it doesn’t work at all.
W:Here’s an advertisem