What changes occurred when human civilizations evolved from hunter-gatherers to settled societies?

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

the treaty of brest-litovsk was a peace treaty signed on 3 march 1918 between the new bolshevik government of russia and the central powers (german empire, austria-hungary, bulgaria, and the ottoman empire), that ended russia's participation in world war i.