21. 

What command is used to display the characteristics of a process?

A. au
B. ps
C. du
D. pid
E. None of the above

22. 

What command is not used to list the files chap01, chap02 and chap04?

A. ls chap*
B. ls chap[124]
C. ls - x chap0[124]
D. ls chap0[124]
E. None of the above

23. 

What command is used with vi editor to replace text from cursor to right

A. S
B. s
C. R
D. r
E. None of the above

24. 

What sign is used to back up over typing errors in vi?

A. !
B. $
C. #
D. @
E. None of the above

25. 

What sign is used to erase or kill an entire line you have typed and start you are on a new line (but not display a new prompt)?

A. !
B. $
C. #
D. @
E. None of the above