单项选择题 An operator needs to change from the /usr/bin to the /var/spool directory. Which of the following commands will accomplish this?（）

单项选择题 The printer associated with the hp5_queue is down for maintenance. Which of the following commands will move the remaining print jobs from hp5_queue to the hp7_queue?（）

单项选择题 After performing a modification on the /etc/ssh/sshd_config file the operator needs to reinitialize the secure shell daemon to enable the new settings. Which of the following is the correct way to achieve this?（）