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.

c. mass = force / accellaration

step-by-step explanation:

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.