Happy Friday…riddle of the day: What goes up and down but never moves?

Clark the Shark written by: Bruce Hale. Clark is a shark with zing, bang, and boom. Clark zooms into school, crashes through the classroom, and is rowdy at recess. Clark loves life – but when his enthusiasm is too much for his friends, Clark’s teacher, Mrs. Inkydink, helps him figure out a way to tone it down. Clark the Shark celebrates boisterous enthusiasm – and knowing when it’s time for indoor voices. https://www.storylineonline.net/books/clark-the-shark/