RAZ， The full name is Reading A-Z, which is a widely popular online graded reading textbook in American schools. It not only helps children transition from listening and speaking to reading, but also covers multiple fields such as common sense, astronomy, geography, history, fairy tales, humanities, and flora and fauna, which is deeply loved by parents and children. RAZ graded reading has become an important tool for improving children's English reading ability due to its systematicity, richness, and suitability.