You ran out of space and added a eighth disk to your SCSI-1 system. When you try to start， the system no longer boots. What is most likely the cause of this problem？（）

Which command （without options） would you use to display how much space is available on all mounted partitions？（）

What command will print a list of usernames （first column） and their corresponding user id （uid， third column） from /etc/passwd？（）

What command with all options and/or parameter will send the signal USR1 to any executing process of  program apache2？（）

Which of the following commands will change all CR-LF pairs in an imported text file， userlist.txt， to Linux standard LF characters and store it as newlist.txt？（）

Which of the following commands makes /bin/foo executable by everyone but writable only by its owner？（）

You wish to kill a process with a PID of 123. Select the command which exiting.（）

Given the following output：  prompt> myapp  [1]+ Stopped myapp  prompt>  Which of the following commands will resume executing the stopped process while allowing the user to continue to type commands at the command prompt？（）

What is the output when the following shell script executes？（）  cat<；<；foobar  Hello foobar  foobar

Many people like the vi text editor but the default bash command line editor recognizes emacs keystrokes. What command entered into a bash initialization file will have bash recognize vi keystrokes after login？（）