______is known to us, bad eating habits are still very common among us students.
The room is too small and it is not fit_________.
It’s her first time that she_______ by the school to participate in the contest.
It is the test system, ______ the teachers,that is to blame for the heavy burden of middle school students nowadays.
He went to town _____sell one of his paintings.
_______all kinds of difficulties,the workers have made rapid progress in the construction of the World Expo 2010 Shanghai.