49. Check the sentences that tell about a systematic operation.
(A) Each person entering the restaurant was given a number and asked to wait his turn.
(B) Some months Greg puts money in the bank, and some months he doesn’t.
(C) The bank mails out monthly statements to all its customers.
(D) They carried off one brick each day until the brick wall was gone.
(E) They checked the machine three times a year.