My knowledge of Hong Kong came only from some movies: a______ of criminals are pursued by the police in the narrow streets and then they have a fight.
It was essential that the application forms ___________ back before the deadline .
_____________ cease(终止) advertising, prices would be significantly reduced.
Much labor would have been saved if the electronic computers_____________ before.
There was a(n)________silence in the live interview,when no one knew what to say to the audience.
Doctors are doing research to find out what happens physically when people______ smoking.