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. Water is one of the most essential ingredients for life on Earth. This reader looks at water in all its forms - in the air, on the ground, in the oceans, in our pipes - and explains how water keeps our lives moving. Use the unique code inside the book to access the online reader, complete with videos and interactive exercises. Plus, download a free e-book version of the reader!