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. Animals find many interesting and efficient ways of moving. This reader discusses how the creatures of our planet navigate the water, land, and air in unexpected and unique ways. Use the unique code inside the book to access the online reader, complete with videos and interactive exercises.Word count: 1751. Lexile Reading Level: 750L.