Ripley's Believe It or Not!-authority on the strange and unusual-and Scholastic present the first of four incredible collections of the world's weirdest, wackiest facts. Believe it! Did you know... ...that hippo sweat looks like blood? ...that a tiger's roar can be heard up to two miles away? ...that golden eagles will attack airplanes that fly too close to their nests? Robert Ripley explo…