As readers grow in skill and ability, they are able to learn more about the world in which they live at the same time as they hone the basic reading skills learned at the emergent and early reading level. Fluent readers will learn about the air, land, oceans, and other aspects of life on Earth and why they matter so deeply to those who live on this planet. Designed to challenge, the text is more detailed and less tied to image than the first two levels of Bookworms. It also features longer words, abstract concepts, and some scientific vocabulary. Readers of Earth Matters will learn much about the world in which they live as well as expand their reading comprehension skills.