A group of young Americans have come to Beijing for a visit. Half of them, ___is, 50 persons, can speak Chinese fluently.
She had just finished her homework __________ her mother asked her to practice __________ the piano yesterday.
The squirrel was lucky that it just missed __________.
Your hand is dirty. It needs __________.
He narrowly escaped __________ in a car accident caused by careless driving.
He got well prepared for the job interview, for he couldn't risk __________ the good opportunity.