Answer:
The answer is C.
Explanation:
It is tangible boundaries (C) because these are natural/physical limitations. The other answers would mean that they were marked or created by humans.
The Second Law of Motion describes what happens to a massive body when it is acted upon by an external force. ... The Third Law of Motion states, "For every action, there is an equal and opposite reaction." This law describes what happens to a body when it exerts a force on another body.
As the Cold War unfolded in the decade and a half after World War II, the United States experienced phenomenal economic growth. The war brought the return of prosperity, and in the postwar period the United States consolidated its position as the world's richest country. Gross national product, a measure of all goods and services produced in the United States, jumped from about $200 thousand-million in 1940 to $300 thousand-million in 1950 to more than $500 thousand-million in 1960. More and more Americans now considered themselves part of the middle class.
The growth had different sources. The automobile industry was partially responsible, as the number of automobiles produced annually quadrupled between 1946 and 1955. A housing boom, stimulated in part by easily affordable mortgages for returning servicemen, fueled the expansion. The rise in defense spending as the Cold War escalated also played a part.
It was the "Smoot–Hawley Tariff Act" that was a disaster because when European nations responded with tariffs on American goods global trade plunged by roughly two thirds
<span> from 1929 levels.</span> This was viewed as exacerbating the Great Depression.
