Theorize why the Byzantine Empire moved toward the feudal system of land and army service for protection

an agricultural laborer legally bound and sold with the land they worked on (unlike slaves who moved separate from land); sought refuge from vassals and kings for protection from invaders

Explanation:

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.

for the united states of america, 1945 to 1964 was a time of high economic growth and general prosperity. it was also a time of confrontation as the capitalist united states and its allies politically opposed the soviet union and other communist countries; the cold war had begun.

explanation: