27.Your lines are all crooked,please use a ______.
A.highlighter B.pencil C.lighter D.ruler
28.To ask where something is form,you are asking for the ______.
A.future B.origin C.past D.present
29.I won not believe you ______ you give me some proof.
A.because B.but C.unless D.and
30.______ the war,there was plenty to eat.
A.Behind B.Back C.Front D.Before