Ben and Ellie have a new teacher. But wait a minute - the new teacher is a dog named Riff! With Riff in charge, reading, writing, and arithmetic are abandoned in favor of lessons in barking, scratching, and digging holes - and Ben, Ellie, and their friends couldn't be happier. Then Mrs. Pink, the principal, comes to check on the class. What will she think of their dog day? High-energy text and bright, graphic illustrations will make readers want to...