单项选择题 A router has two FastEthernet interfaces and needs to connect to four vlans in the local network.How can you accomplish this task，using the fewest physical interfaces and without decreasing network performance？（）

单项选择题 使能轮询DCC的命令是（）。

多项选择题 A company is installing IP phones. The phones and office computers connect to the same device. To ensure maximum throughput for the phone data, the company needs to make sure that the phone traffic is on a different network from that of the office computer data traffic. What is the best network device to which to directly connect the phones and computers, and what technology should be implemented on this device (Choose two.)（）。