Problem: Avicenna:

Ibn Sina's first appointment was that of physician to the emir, Nuh II, who owed him his recovery from a dangerous illness (997). Ibn Sina's chief reward for this service was access to the royal library of the Samanids, well-known patrons of scholarship and scholars. When the library was destroyed by fire not long after, the enemies of Ibn Sina accused him of burning it, in order for ever to conceal the sources of his knowledge. Meanwhile, he assisted his father in his financial labors, but still found time to write some of his earliest works.

who dit Ibn Sina treat in the 9th century?
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A: unanswerable


Problem: Ectosymbiosis, also referred to as exosymbiosis, is any symbiotic relationship in which the symbiont lives on the body surface of the host, including the inner surface of the digestive tract or the ducts of exocrine glands. Examples of this include ectoparasites such as lice, commensal ectosymbionts such as the barnacles that attach themselves to the jaw of baleen whales, and mutualist ectosymbionts such as cleaner fish.
What mutualist ectosymbionts clean the barnacles that attach themselves to the jaw of baleen whales?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Other sections of society included the nobility, clergy, and townsmen. Nobles, both the titled nobility and simple knights, exploited the manors and the peasants, although they did not own lands outright but were granted rights to the income from a manor or other lands by an overlord through the system of feudalism. During the 11th and 12th centuries, these lands, or fiefs, came to be considered hereditary, and in most areas they were no longer divisible between all the heirs as had been the case in the early medieval period. Instead, most fiefs and lands went to the eldest son.[R] The dominance of the nobility was built upon its control of the land, its military service as heavy cavalry, control of castles, and various immunities from taxes or other impositions.[S] Castles, initially in wood but later in stone, began to be constructed in the 9th and 10th centuries in response to the disorder of the time, and provided protection from invaders as well as allowing lords defence from rivals. Control of castles allowed the nobles to defy kings or other overlords. Nobles were stratified; kings and the highest-ranking nobility controlled large numbers of commoners and large tracts of land, as well as other nobles. Beneath them, lesser nobles had authority over smaller areas of land and fewer people. Knights were the lowest level of nobility; they controlled but did not own land, and had to serve other nobles.[T]
In this period, who usually inherited fiefs?
A: the eldest son


Context and question: Windows 8 was distributed as a retail box product on DVD, and through a digital download that could be converted into DVD or USB install media. As part of a launch promotion, Microsoft offered Windows 8 Pro upgrades at a discounted price of US$39.99 online, or $69.99 for retail box from its launch until January 31, 2013; afterward the Windows 8 price has been $119.99 and the Pro price $199.99. Those who purchased new PCs pre-loaded with Windows 7 Home Basic, Home Premium, Professional, or Ultimate between June 2, 2012 and January 31, 2013 could digitally purchase a Windows 8 Pro upgrade for US$14.99. Several PC manufacturers offered rebates and refunds on Windows 8 upgrades obtained through the promotion on select models, such as Hewlett-Packard (in the U.S. and Canada on select models), and Acer (in Europe on selected Ultrabook models). During these promotions, the Windows Media Center add-on for Windows 8 Pro was also offered for free.
Which PC owners could purchase a Windows 9 Pro uprgrade for $14.99?
Answer: unanswerable


Question: The Gregorian calendar improves the approximation made by the Julian calendar by skipping three Julian leap days in every 400 years, giving an average year of 365.2425 mean solar days long. This approximation has an error of about one day per 3,300 years with respect to the mean tropical year. However, because of the precession of the equinoxes, the error with respect to the vernal equinox (which occurs, on average, 365.24237 days apart near 2000) is 1 day every 7,700 years, assuming a constant time interval between vernal equinoxes, which is not true. By any criterion, the Gregorian calendar is substantially more accurate than the 1 day in 128 years error of the Julian calendar (average year 365.25 days).
Is there an answer to this question: How many days must be skipped to align the calendar with mean solar days in a year?

Answer: three Julian leap days


QUES: Geology did not undergo systematic restructuring during the Scientific Revolution, but individual theorists made important contributions. Robert Hooke, for example, formulated a theory of earthquakes, and Nicholas Steno developed the theory of superposition and argued that fossils were the remains of once-living creatures. Beginning with Thomas Burnet's Sacred Theory of the Earth in 1681, natural philosophers began to explore the idea that the Earth had changed over time. Burnet and his contemporaries interpreted Earth's past in terms of events described in the Bible, but their work laid the intellectual foundations for secular interpretations of Earth history.

What book did Thomas Burnet right in 1681?
What is the answer?
ANS:
Sacred Theory of the Earth