Answer:
the use of poison gas and machine guns
Explanation:
Aerial attacks weren't really a thing, unrestricted submarine warfare was a reason why the US joined the war but not a factor in high casualty rates, and blimps using direct artillery fire isnt as practical as machine guns and poison gas
What is it do you need help
Answer:
You don't really have any multiple choice, so here's an explanation. The entire reason for early sports was to teach younger generations how to work in a team, so that when they worked in industrial factories and businesses, they had already learned teamwork. Pro sports began to rise in popularity as rivalries between regional areas in the US rose through the progressive era. These rivalries had existed since the antebellum era in America before the civil war. Plus, there weren't many forms of entertainment in the industrial areas, and sports(watching or playing) was a great way to keep individuals off the streets and in a better area. Thus, pro sports popularity rose in the 1900s.
The more allies Rome had the more territory it could have under its control. Also the other places bring new cultures into Rome so that it could grow in that aspect as well.
