单项选择题
A technician receives an urgent call that the switch in accounting is down. Which of the followingshould the technician do FIRST to troubleshoot this issue?（）
A. Identity symptoms and problems B. Document the process and solutions C. Establish the most probable cause D. Escalate if necessary.
单项选择题 Which of the following is a performance optimization technology?（）
单项选择题 Which of the following is an example of a MAC address?（）
多项选择题 Which of the following is a correct IP ACL? (Select TWO)（）
