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Currently printed denominations are $1, $2, $5, $10, $20, $50, and $100. Notes above the $100 denomination stopped being printed in 1946 and were officially withdrawn from circulation in 1969. These notes were used primarily in inter-bank transactions or by organized crime; it was the latter usage that prompted President Richard Nixon to issue an executive order in 1969 halting their use. With the advent of electronic banking, they became less necessary. Notes in denominations of $500, $1,000, $5,000, $10,000 and $100,000 were all produced at one time; see large denomination bills in U.S. currency for details. These notes are now collectors' items and are worth more than their face value to collectors.
When were bills above the $100 denomination withdrawn from circulation?
A: 1969

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Ibn Khaldun can be regarded as the earliest scientific systematic sociologist. The modern sociology, emerged in the early 19th century as the academic response to the modernization of the world. Among many early sociologists (e.g., Emile Durkheim), the aim of sociology was in structuralism, understanding the cohesion of social groups, and developing an "antidote" to social disintegration. Max Weber was concerned with the modernization of society through the concept of rationalization, which he believed would trap individuals in an "iron cage" of rational thought. Some sociologists, including Georg Simmel and W. E. B. Du Bois, utilized more microsociological, qualitative analyses. This microlevel approach played an important role in American sociology, with the theories of George Herbert Mead and his student Herbert Blumer resulting in the creation of the symbolic interactionism approach to sociology.
What was Ibn Khaldun's profession?
A: scientific systematic sociologist

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Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.
Why do broad winged birds avoid geographical barriers?
A: lack of thermal columns

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While the churches eventually worked out their differences and came to an initial agreement, both Nicholas I of Russia and Napoleon III refused to back down. Nicholas issued an ultimatum that the Orthodox subjects of the Empire be placed under his protection. Britain attempted to mediate, and arranged a compromise that Nicholas agreed to. When the Ottomans demanded changes, Nicholas refused and prepared for war. Having obtained promises of support from France and Britain, the Ottomans officially declared war on Russia in October 1853.
What month did the Ottomans declare war on Russia?
A:
October