Answer and Explanation:
1. The industrial revolution allowed the full manioulation of iron and steel, which allowed the construction of a vast artillery network that gave the first world war a firepower that had never been seen before and that can transform that war into most violent and deadly war ever seen at the time. The industries took on the mission of enriching the army with tanks, airplanes and chemical weapons that allowed violent bombing and ammunition. Believe that 80% of those killed were victims of artillery fire.
2. Although Archduke Ferdinand's assassination was the trigger for the first world war, other factors prior to this assassination already promoted pre-war tension. Among these factors, we can mention imperialism, which is characterized by the expansion of European governments in other regions where they could dominate, subdue, control and exploit. This generated a lot of wealth, which made European countries compete and generate hostilities with each other. In addition, nationalism, military alliances and economic rivalries influenced the tension between European countries. We cannot leave out the Balkan issue, which was one of the main factors of tension among European nations, since it made the continent's greatest powers dispute the control of the Balkans, a region that promoted the union between Asia and Europe.
3. Nationalism emerged through speeches full of fallacies and authoritarian politicians that created stories about the supremacy and superiority of one European nation over the others. This arose mainly within nations that, in some way, depended on or were being dominated or occupied by others. These speeches generated in the population a strong feeling of national belonging, which created many idological conflicts. The greatest example of this is what happened in Serbia, which was a country of orthodox Catholic tradition, but which was not independent and lived under the control of the Austro-Hungarian Empire which did not meet the same religious concepts.