It was a serious mistake, ______ caused by carelessness.
His father got very __________ when he made a mistake again.
The young teacher says this is __________ for the beginners.
In the __________ of proof, the police could not take action against the man.
—All the lights have gone out in the office building. —Yes, they have __________ electricity.
You should try to __________ new circumstances as quickly as you can.