Answer:
After World War I,
B. The economy crashed because the railroads failed.
Explanation:
Why the railroads were so important-
The railroad industry was the largest employer outside agriculture in the US and involved large amounts of money and risk.
A large infusion of cash from speculators caused spectacular growth in the industry and in teh construction of docks, factories, and ancillary facilities.
Vietnam experinced war in the 60's
There are 3 powers of land building
Explanation:
▪︎new land being formed
▪︎either by tectonic uplift or by lava flows
▪︎by the deposition of sediment