All human civilization is originated from the African Region and started to migrate to Asia, then to America and Europe
The daily life in the early civilization is actually really similar. And started to differ when they entered the Agricultural period because of the food resource that available near that region (Americans use wheat, Asians used grains, and the Africans used corns)
The vault was a structure consisting of arrangements of arches which allowed the Romans to connect any room with the arches because they usually formed a ceiling or roof
Far eastern Russia is for sure the answer
The answer Americans would get involved in all wars