Article: Catalan pronouns exhibit TV distinction, like all other Romance languages (and most European languages, but not Modern English). This feature implies the use of a different set of second person pronouns for formality.

Question: What does this imply the use an extra group of pronouns for?
Ans: formality

Article: The army is led by a civilian Secretary of the Army, who has the statutory authority to conduct all the affairs of the army under the authority, direction and control of the Secretary of Defense. The Chief of Staff of the Army, who is the highest-ranked military officer in the army, serves as the principal military adviser and executive agent for the Secretary of the Army, i.e., its service chief; and as a member of the Joint Chiefs of Staff, a body composed of the service chiefs from each of the four military services belonging to the Department of Defense who advise the President of the United States, the Secretary of Defense, and the National Security Council on operational military matters, under the guidance of the Chairman and Vice Chairman of the Joint Chiefs of Staff. In 1986, the GoldwaterNichols Act mandated that operational control of the services follows a chain of command from the President to the Secretary of Defense directly to the unified combatant commanders, who have control of all armed forces units in their geographic or function area of responsibility. Thus, the secretaries of the military departments (and their respective service chiefs underneath them) only have the responsibility to organize, train and equip their service components. The army provides trained forces to the combatant commanders for use as directed by the Secretary of Defense.

Question: How many military services beling to the Department of Defense?
Ans: four

Article: While outer space provides the most rarefied example of a naturally occurring partial vacuum, the heavens were originally thought to be seamlessly filled by a rigid indestructible material called aether. Borrowing somewhat from the pneuma of Stoic physics, aether came to be regarded as the rarefied air from which it took its name, (see Aether (mythology)). Early theories of light posited a ubiquitous terrestrial and celestial medium through which light propagated. Additionally, the concept informed Isaac Newton's explanations of both refraction and of radiant heat. 19th century experiments into this luminiferous aether attempted to detect a minute drag on the Earth's orbit. While the Earth does, in fact, move through a relatively dense medium in comparison to that of interstellar space, the drag is so minuscule that it could not be detected. In 1912, astronomer Henry Pickering commented: "While the interstellar absorbing medium may be simply the ether, [it] is characteristic of a gas, and free gaseous molecules are certainly there".

Question: What was originally believed the heavens were filled with?
Ans: aether

Article: Contact with European diseases such as smallpox and measles killed between 50 and 67 per cent of the Aboriginal population of North America in the first hundred years after the arrival of Europeans. Some 90 per cent of the native population near Massachusetts Bay Colony died of smallpox in an epidemic in 16171619. In 1633, in Plymouth, the Native Americans there were exposed to smallpox because of contact with Europeans. As it had done elsewhere, the virus wiped out entire population groups of Native Americans. It reached Lake Ontario in 1636, and the lands of the Iroquois by 1679. During the 1770s, smallpox killed at least 30% of the West Coast Native Americans. The 177582 North American smallpox epidemic and 1837 Great Plains smallpox epidemic brought devastation and drastic population depletion among the Plains Indians. In 1832, the federal government of the United States established a smallpox vaccination program for Native Americans (The Indian Vaccination Act of 1832).

Question: Who were the Native Americans exposed to smallpox because of?
Ans:
Europeans