---Tom, must you have the light______ all night? It’s really a waste. ---Sorry, I won’t do it again.
What’s the name of the sport __ you try to get the other person down on the floor.
___ is a good idea to keep quiet about the problem.
You’d better find an English pen friend ___ improve your writing.
There are 2100 students __ all in our school.
You’d better __ electricity; it would be dangerous.