To the left of each awk command below, write the number of the corresponding sed command and the letter of the corresponding grep/tr/sort/\&c. command. Assume no space at the beginning or end of input lines. If any is not possible, mark it with an ' X '. To the left of each awk command below, write the number of the corresponding sed command and the letter of the corresponding grep/tr/sort/\&c. command. Assume no space at the beginning or end of input lines. If any is not possible, mark it with an ' X