Paper produced every year is ________ the world’s production of vehicles.
—When did he leave the classroom?—He left _____you turned back to write on the blackboard.
____he thought he was helping us with the work, he was actually in the way.
Hearing his words ,I couldn’t decide _____or remain .
Questions and exercises are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.
—Will you go to Mary’s birthday party?—No, ____ invited, I can’t go to it. I’ll be too busy then.