The answer you're looking for is c.
Answer:
The North Vietnamese attacked the US Navy in the Gulf of Tonkin. This problem lead to the USA beginning to start the war.
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Answer:
Nuclear Arms race.
Extensive spying techniques.
Proxy Wars were fought under the influence of the two world powers.
Explanation:
Both countries have used comprehensive methods of spying against each other. It is estimated that in all of the numerous proxy wars waged between the United States of America and the Soviet Union, more than eleven million civilians were killed. The U.S. had a national intelligence agency named the Central Intelligence Agency (CIA) and the Soviets had the KGB. The Space Race emerged from the Cold War and the Internet was a direct result of that. During the Cold War there was a spike in nuclear weapons.
Answer:The main power was KMT and it was extremely corrupted. Weak central government, lack of modern industrial base, various levels of corruption. Chinese troops when trained and decently equipped performed well.
Answer:
serfdom, condition in medieval Europe in which a tenant farmer was bound to a hereditary plot of land and to the will of his landlord. The vast majority of serfs in medieval Europe obtained their subsistence by cultivating a plot of land that was owned by a lord. This was the essential feature differentiating serfs from slaves, who were bought and sold without reference to a plot of land. The serf provided his own food and clothing from his own productive efforts. A substantial proportion of the grain the serf grew on his holding had to be given to his lord. The lord could also compel the serf to cultivate that portion of the lord’s land that was not held by other tenants (called demesne land). The serf also had to use his lord’s grain mills and no others.
Explanation:
https://www.britannica.com/topic/serfdom