Because of too many differences between the two sides, a lot of questions are still left ________.A in the air B on the air C by the air D through the air
Don’t you know that Australia was, as a matter of fact, _________ used to be a nation of prisoners!
_______________, the players began the game.
Having checked the doors were closed, and _______ all the lights were off, the boy opened the door to his bedroom.
—Where are we going for the National Day,the mountains or the sea? —Either will be fine with me.
You are driving too fast. Can you drive_________?