Explore the wide-ranging work of the US Military in this high-interest series. Readers learn about each force's history, the types of missions its members do, and the equipment and training these missions require. Short paragraphs of easy-to-read text are paired with plenty of photos to make reading engaging and accessible. Each book also includes a table of contents, fun facts, sidebars, comprehension questions, a glossary, an index, and a list of resources for further reading. Apex books have low reading levels (grades 2-3) but are designed for older students, with interest levels of grades 3-7.