With Shanghai World Expo drawing near, volunteers are making use of every minute to ________ their foreign language because language volunteers must pass a written test.
Everyone in our class was working hard and doing what we could ______ a good college.
It is said that the early European playing-cards ______ for entertainment and education.
Gaddafi’s failure in Sirte _________ him the last opportunity to reestablish the government.
I suppose by the time I come back next year, all these old houses south of the Baoshehe River ________ down.
The ability _______ an idea is as important as the idea itself.