In this title, readers will examine the technology used by military forces during World War I. Engaging text introduces readers to trench engineering, rifles, machine guns, cannons, howitzers, mortars, mustard and chlorine gas, gas masks, tanks, U-boats, the machine gun/airplane propeller synchronization system, and the roles they played in military campaigns. A short history of the war is also included. Aligned to Common Core standards and correlated to state standards. Checkerboard Library is an imprint of Abdo Publishing, a division of ABDO.