I have been struggling to answer these questions and would really appreciate help to answer them. Thank you!

Question #18: The commands "vi", "sed", and "grep" all use the same format for regular expressions. which line below would match "[^ ]ra" ? I will not, will not, with a goat I do not like them with a mouse I do not like them with a fox OI will not eat them on a train OI will not eat them in a house. I do not like them in a box OI will not eat them in the rain I could not, would not, on a boat Question #19: I want to find all words that start and end with the same letter. What command will work? Osed 'la-z]*[a-z]S' /usr/share/dict/words Ogrep '[a-z]*[a-z]S' /usr/share/dict/words Osed 'la-z].*[a-z]S' /usr/share/dict/words None of the other answers is correct Ogrep 'A..*.$' /usr/share/dict/words O sed ..S' /usr/share/dict/words Ogrep '[a-z].*[a-z]S' /usr/share/dict/words Question #20: which is a grep-like regular expression which will match lines that include the character "/"? Cannot be done