This is the economic system.
An example of an economic system is "capitalism" - where individuals own the capital and produce to increase their wealth or "communism" where the means of production belong to all people and are controlled by the government.
The answer is D because a serf is a peasant, or farmer that has to pay taxes and practically has no rights under the law. 95% of the English population in the 1400s were serfs.
Mercosur is a shorter form of "Mercado Comun del Sur" - Common Market in the South, which is a trading bloc (area with free trade and no tariffs or restrictions) in South America.
The correct answer is:
<span>an arrangement to increase economic cooperation</span>
The answer is : monocular depth
Monocular depth affect the perception that is held by an individual on<u> how far an object is located based on how big</u> the object look like in that individual's vision.
When the driver cross the railroad, the driver most likely thought that the train is still located far away form him/her because it looks small in the driver's perception. He misjudge it and caused the crash in the end.
