It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
David, ________yourself. Did you forget the school rules?
Look at the pride on Tom's face. He ________ to have been praised by the manager just now.
________ with the courage and determination of the young cancer patient, many people left messages in his microblog, encouraging him to fight with the disease.
Mike is kind, determined and full of energy. ________, I can't speak too highly of him.
Every day we are flooded _____ all kinds of sounds, ____ which most are noise.