elebrating the 100th birthday of the United States. The biggest party is in Philadelphia at the World's Fair, where the latest and greatest inventions are on display for all to see. Alexander Graham Bell is headed to the fair to demonstrate his invention - a talking machine he calls the telephone. But will anyone come to see him at the world's most important science fair? And more importantly, will his machine work? This Step 3 reader celebrates the resilient, quirky spirit of inventors.