A user’s print jobs default to PRINTER_A.The user wants to change their default printer to PRINTER_B.How can the system administrator change the user’s default printer to PRINTER_B？（）

单项选择题A 1500 page print job was sent to the  pcl  queue. The job was running for several minutes before it was determined that the job was not needed. What can be done to delete the job？（）

A.kill 201
B.cancel 201
C.disable pcl
D.rm /var/spool/lpd/STDIN.27648

单项选择题Given the following scripts， what output would be generated？（）

A.The sky is red.
B.The sky is blue.
C.The sky is green.
D.The sky is yellow.

单项选择题Given the following scripts， both found in  usr local bin， what would the output be when executing  usr local bin script1？（）

A.dog cat
B.dog fish
C.mouse cat
D.mouse fish

单项选择题Howcanpermissionsbesetupon tmpsothatausercannotdeleteanotheruser’sfiles？（）

A.chmod +s /tmp
B.chmod 775 /tmp
C.chmod 1777 /tmp
D.chmod 4755 /tmp

单项选择题While installing an application， the administrator is instructed to perform two final tasks prior to starting the application：   1.Set the ownership of a file named ’control_file’ to be owned by the user ’database’ and the group ’appsrvr’.   2.Change the permissions of ’control_file’ to 0766.   After these two tasks have been completed， what will the file permissions look like when ’ls -l control_file’ is executed？（）

A.-rwxrw-rw- 1 database appsrvr 4913 Mar 17 08：24 control_file
B.-rw-r--r-- 1 appsrvr database 4913 Mar 17 08：24 control_file
C.-rw-r--r-- 1 database appsrvr 4913 Mar 17 08：24 control_file
D.-rwxrw-rw- 1 appsrvr database 4913 Mar 17 08：24 control_file