It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
—Don't __________ your friends' trust, or you will lose friendship. —What you said is right.
Do you approve of the idea that success can be measured __________ money alone?
She is only a (n) __________, not a friend of mine.
It was __________ back home after the experiment.
Do you think the concert last weekend was of __________?