Wind-driven turbine vent. 1  Wind-driven roof vents will pull more air from the attic, but only when the wind is blowing. 2  Flat roof vents have no moving parts to break or squeak, but don't vent as much air as wind-driven vents.
An airplane or aeroplane (informally plane) is a powered, fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Commercial aviation is a massive industry involving the flying of tens of thousands of passengers daily on airliners.
War in the Air. World War I was the first war where the airplane was used. Initially, airplanes were used to observe enemy troops. However, by the end of the war they were used to drop bombs on troops and cities. They also had mounted machine guns that were used to shoot down other planes.anks were first introduced in World War I. These armored vehicles were used to cross No Man's Land between the trenches. They had mounted machine guns and cannon. The first tanks were unreliable and hard to steer, however, they became more effective by the end of the war.