Penguins that exchange wedding rings A fish that doesn't swim Learn all about the bizarre and unexpected behavior of animals from around the world. Cambridge Discovery Education Interactive Readers are the next generation of graded readers - captivating topics, high-impact video, and interactive exercises designed to motivate and engage. These 96 leveled (A1-B2+), highly engaging titles feature Discovery Education videos that are fully integrated into the pedagogy of the readers. Choose from four formats: book plus access code for online content; online only; iOS app; and Android app. The online version of these readers comes complete with a learning management system - class creation, progress tracking, gradebook, and more - which frees teachers from the mundane task of homework correction, and gives students interactive practice anytime, anywhere.