What were 4 important technological innovation of world war 1 How were they used?

Four important technological innovations of World War I included the tank, machine gun, airplane, and poison gas. Tanks were used to break through enemy trenches and fortifications, providing mobility and protection for infantry. Machine guns changed the dynamics of warfare by allowing for rapid-fire suppression of enemy troops, contributing to the high casualty rates. Airplanes were initially used for reconnaissance but evolved to include bombing and dogfighting, while poison gas introduced a new level of terror and lethality on the battlefield.