The huge wheels, powerful engines, and loud noises of working machines seem to entrance children for hours. Now young students can pore over color photos as they learn about their favorite machines--inside and out. Each book builds vocabulary as it describes, in simple language, the basics of a machine: what it looks like, what it's used for, and how it works. Additional features to aid comprehension include a table of contents, a phonetic glossary, sources for further research, an index, and an introduction to the author.