Identify the importance of tanks, planes, gases, and the machine gun in ww1

Well, all of these thing were advancement in military! In past wars you didn't have these things! Planes lead to things called "dog fights" which just meant airplane fights in the air. Tanks made it so mobility was increased, they could even roll right over barbed wire, not to mention the guns attached to a tank! Machine guns made it possible to shoot hundreds of rounds of ammo, in less than a minute, so you can well imagine what happened because of that! While WW1 itself was cruel, gas was a big part of this! They used gas called mustard gas, and what it would do was create blisters all over a persons body! Or, they used tear gas, which basically caused a build up of fluid in the lungs. Gas was said to have killed over 91,000 people in WW1 

I hope this helps!