From the garbage trucks that help keep our towns and cities clean to the semi trucks that pull trailers full of important resources across the nation, big trucks play a major role in the way we live.Readers (Grades 3-5) will discover how trucks were invented and how they have been improved over time. They will also find out how people hauled heavy loads before trucks existed, what kinds of things engineers have to consider when designing new trucks, and why some of history's biggest trucks were created.