The correct answer is Timbuktu. It became the greatest city because it was a melting pot for traders from all possible nations because it was wealthy and developed compared to other places. It was a cultural and a trading center because the ruler knew how to rule properly and made Timbuktu one of the greatest cities in the world.
Here are some of the weapons first used in WWI. Airplanes, Derigables, poison gas, flamethrower, and tanks. Other weapons that were invented before the war but not used on a wide scale or were not reliable until WWI were the machine gun, submarines, torpedoes, small mortars and very large caliber artillery. WWI also saw the use of the radio for the first time in combat conditions.
The development of new ways of telling social reality, and writers sought connections between their work and the social environment and context in which their lives were spent. It was mostly through stories and novels that literary productions were embodied.
Most landforms change very slowly over many, many years. New mountains have formed as the plates of Earth's crust slowly collided, and others have been worn away by weathering and erosion. ... Floods and landslides can change landforms in a matter of seconds. Volcanic eruptions can also change landforms quickly.