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. It's in our shoes, cars, bikes, golf balls, clothing, kitchens . . . what would we do without rubber? Learn about where rubber comes from, how we use it, and how we depend on it more and more. 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!