1. [单选题]You are a senior network administrator at Ezonexam, and while performing the password recovery procedure on your 2500 series Cisco router, you type in the following command:o/r 0x2142
A. What is the purpose of this command?
B. It is used to restart the router.
C. It is used to bypass the configuration in NVRAM.
D. It is used to enter ROM Monitor mode.
E. It is used to view the lost password.
F. It is used to save the changes to the configuration.
2. [单选题]PPP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
