—It has been nation-widely required that every student ______ have daily exercise for one hour.—Yeah.It is high time that we ______ special attention to physical exercise.

— Mary’s got mad and has been sent to the mental hospital. Did you tell her boss about that?— Yes, but I _____ her husband first.

It is usually not quite cold in this area in March, but sometimes temperature ____be very low.

The poor boy    the test again; in that case, his mother will be very disappointed.

_______ we _______ the new policy for economy, we would never have bought the house.