The time is approaching_______we will have to leave the lonely island.
He set out early after supper_________ be late for the film.
You’d better put things back______. Otherwise, it will be difficult to find them.
It is_____the pupils do in their spare time_____ really______ them to take their place in society as citizens when they grow up.
The tower_____ in the 1800s is the oldest building in this area.
The computer system ____suddenly while he was searching for information on the Internet.