内容简介
HappyBirthday,Arthur!Arthurishavingagymnasticspartyforhisbirthday,withprizesforbalancing,tumbling,andropeclimbing.Arthurissurethathewillwintheprizeforbestall--aroundgymnast.Buthislittlesister,Violet,andherfriendWilmahavebeenpracticing-andtheymayhaveasurpriseinstore....