* Tanks were first used in the First World War. * Poison gasses were first used in the First World War. * Airplanes were first used as weapons in the First world War. * Machine Guns * Carriers we're first used in World War 1.

There may be other answers Note: The Maxim Gun, the first machine gun, saw much use in Africa with the British, long before the First World War - having been invented in 1884 and first used by British forces in Matabeleland in what was known as The First Matabele War, in 1893 - 94. As Hilaire Belloc wrote in "The Modern Traveller" (published 1898) "Whatever happens we have got

The Maxim Gun, and they have not."