Series Overview- This high-interest, educationally vetted series of beginning readers features the magnificent images of National Geographic, accompanied by texts written by experienced, skilled children's book authors. Each reader includes a glossary and interactive features in which kids get to use what they've learned in the book. Level 1 books reinforce the content of the book with a kinesthetic learning activity. In Level 2 books readers feature slightly higher level text and additional vocabulary words. Level 3 readers have more layers of information to challenge more proficient readers.