What command will an operator use to check if the system has NFS3 filesystems currently defined?（）

单项选择题An operator notices that a job on the system is causing poor performance. The job is a root process and the administrator has concluded it is not important and can be stopped. Shortly after stopping the process, it starts again. Which of the following commands will list repeating scheduled tasks?（）

A. at -l
B. jobs -l
C. sched -l
D. crontab -l

单项选择题Which command enables a user to exit the vi editor, overwriting the existing file without prompting for confirmation?（）

A. :w
B. :qw
C. :x!
D. :we!