We use machines every day, but most of us don't understand how they work. When they break down, most of us have no idea how to fix them. Mechanics are the masters of machines. Readers learn that mechanics work on vehicles, including cars, boats, and buses. They use special tools to take them apart and fix what's wrong, and they use their experience and technology to diagnose problems. They often work long hours, sometimes in bad weather, to get us where we need to go. Your readers will see that mechanics keep our world moving and growing.