KEY to the exercises m)He checks carefully every evening to make sure that all the doors are locked. n)They decided to go to Xi'an by plane instead of by train. o)Come to think of it,we really can't wait any more. p)When she heard that her son was killed in the air crash, she burst into tears. q)Don't take things for granted.You'd better look it up in a dictionary. r)The comrades showed great concern for him.But he took it all for granted.m)He checks carefully every evening to make sure that all the doors are locked. n) They decided to go to Xi'an by plane instead of by train. o) Come to think of it, we really can't wait any more. p) When she heard that her son was killed in the air crash, she burst into tears. q) Don't take things for granted. You'd better look it up in a dictionary. r) The comrades showed great concern for him. But he took it all for granted