为查看控制器状态，你需要输入哪个命令?（）

A.show running-config

B.show startup-config

C.show version

D.show controllers

关于帧中继的说法，正确的是（）

A.速率最大为1Mbit/s

B.不提供差错校验功能

C.可以偷占带宽

D.数据传输质量高于DDN

都是NAT的地址转换方式()。

A.静态地址转换

B.动态地址转换

C.复用动态地址

D.端口地址转换

When files are transferred between a host and an FTP server, the data is divided into smaller pieces for transmission. As these pieces arrive at the destination host, they must be reassembled to reconstruct the original file. What provides for the reassembly of these pieces into the correct order?

A．The sequence number in the TCP header

B．The Start Frame. Delimiter in the 802.3 Preamble

C．The TTL in the IP header

D．The acknowledgement number in the segment header

E．The frame. check sequence in the Ethernet frame. trailer

While troubleshooting a connectivity problem on the network, you issue the ping command from your PC command prompt, but the output shows "request times out."

At which OSI layer is this problem associated with?

A．The data link layer

B．The application layer

C．The access layer

D．The session layer

E．The network layer