Vocabulary: Punching bag

The door to the classroom opened, and we all turned around. Mr Burne stood there. Then he saw Bethany, who was still holding his notebook in the air like, well, like a weapon. She gasped, but it was like she couldn’t move. None of us could move. For a moment, I wondered if Mr Burne’s hair was going to fall out, or if he would shout at us. But he just walked over, took the…