13. They were surprised that a child ______ work out the problem while they themselves couldn’t.
—Do you know Ann Watterson very well? —Yes, she used to be ______ coach and in ______ charge of our school team.
—May I ask you something about the accident? —Sure. ___________!
Seeing the _____ dog, the little boy stood there with a _____ expression on his face.
Almost _______ of the students in this class wear glasses, that is, _______ of them.
Thewe recycle, the we waste.