The 1920s was a period of economic prosperity for the united states as a result of? a. world war l b. world war ll c. cold war d. civil war

Well, number 1, the 1920s was not economically prosperous until the start of the Lend-Lease Act, which employed large amounts of people in producing equipment for the Allies.

B. World War II is your answer, because WWI had already ended at 1918, and the Cold War was after 1945.

~

i think it would be reparing roads  

explanation:

the addition to geographic boundaries that might have  kept the people of the huang river civilization from traveling to far distance region is that they had learned about the other river valley civilizations but feared contact would bring invasion.

hope this .

plz give me brainliest!