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. Sharks, puffer fish, polar bears, and the world's deadliest animal - the mosquito. Learn all about deadly animals, both big and small. Use your unique code inside the book to access the online reader, complete with videos and interactive exercises. Word count: 1598. Lexile reading level: 540L.