Fortunately somebody who happened to be passing by called the fire department __________the fire broke out.
___used to be thought that the earth was square.
Does___matter whether he can finish the job on time?
Tom’s mother kept telling him that he should work harder, but ___didn’t help.
In fact, ___is a hard job for the police to keep order in an important football match.
Someone is ringing the doorbell. Go and see ______.