Could someone help me proof-read this, and see if there is any grammatical errors?

There were many new weapons developed in World War I. One of these weapons was a tank. New tanks were being produced and used in World War I. Both the Allies and the enemies used them. The countries that used tanks in World War I were the British, the French, and the Germans. The French tank was the Renault FT-17. The Renault FT-17 was very slow and had a crew of 2 men. It was the first tank to possess a fully rotating turret. The FT-17 did not have good armor but did travel well across difficult terrain. The British tank was the Mark I. The Mark I was designed to cross over trenches and to resist small-arms fire. It did not have a good armor but was able to carry supplies for soldiers. The German tanks were A7V’s. The German’s nicknamed it the “Monster”. The A7V had a crew of about 16 people and weighed 31 tons. The A7V was fast compared to other tanks such as the Mark I and the FT-17 but it had a lot of trouble moving over difficult terrains, unlike the other tanks. There wasn’t too many built and it was used late in World War I because the German’s had focused more on their anti-tank weapons. All of the crew members inside of all these tanks had to suffer. It was very crowded inside the tanks and all the fumes from the tank would build up inside. Every tank was very slow and it took a while to get places when driving one even though most tanks did move easy over difficult terrain. They all didn’t have that great of armor but they all had powerful turrets.