KENNETT SQUARE, Pa. (AP) -- The cheerful sign outside Jane Cornell's summer school classroom in Pennsylvania's wealthiest county reads "Welcome" and "Bienvenidos" in polished handwriting. Inside, giggling grade-schoolers who mostly come from homes where Spanish is the primary language worked on storytelling with a tale about a crocodile going to the dentist. This poster and classroom at the Mary D. Lang Kindergarten Center are a subtle representation of America's changing school demographics. For the first time, U.S. public schools are projected to have more minority students than non-Hispanic whites, a shift largely fueled by growth in the number of Hispanic...