Answer: The Invention of the timer gear on fighter aircraft, the monoplane and more advanced aircraft such as fighter and bombers. the tank, the submarine, the machine gun, the dreadnought, the semi-auto rifle, chemical weapons, and the sub-machine gun. The tank, the submarine, the machine gun, semi-auto rifle, and the sub-machine gun are all still used today.
1.<span>Few social changes </span>2.<span>Little problem of spread disease </span><span>3.More dangers from animals and accidents 4.More surplus food 5.Few technological changes</span>
