German use of submarines to blockade britain during world war i led to
a german victory.
trench warfare
a war of attrition
the united states entering the war.

all of the choices are correct

the correct answer is a) egypt and china.

egypt and china are two of the world’s oldest civilizations known by man. both ancient empires have left a great historic and cultural legacy to the world through archeology. both civilzations developed complex social relations, had deep religious beliefs, had dominion of agriculture and left writing records to understand their customs and culture.

among the requirements to consider a civilization, we find urbanization, writing records, a place of residence, agriculture methods, technological specialization, means of transportation, currency, population density, social stratification, and political integration.