—Peter looked tired and a little absent-minded in class. —He _____ too late.
I think that something has to be done to stop the air from being polluted, ______ ?
It has been reported that some government leaders ______ their authority and position to get illegal profits for themselves.
Let's learn to use the problem we are facing ______ a stepping-stone to future success.
His novels sell best and have made him famous, but before that no one could have imagined how great a role he ______ in the literary world.
When dealing with students, teachers are supposed to adopt ______ and caring approaches, as they are unique young individuals of different personalities.