Airplanes ,machine guns ,poisonous gas these military weapons were first used in what war? a) world war i b) world war ii c) the civil war d) the spanish-american war

Airplanes, Machine Guns, & Poisonous Gas were first used in WW1.

Airplanes: Aircrafts was used all the time during the war, esspecially for artillery spotting.

Machine: Machine guns were designed for people to use in WW1, such as the lewis gun which had a 47 or 97 round pan magazine

Poisonous Gas: Phosgene, Chlorine, & Mustard Gas was used commonly during WW1.

its c

he sent troops to protect the students as they entered the school.