The problem: Answer a question about this article:
The axiom of foundation established that every set can be constructed from the bottom up in an ordered succession of steps by way of the principles of Zermelo and Fraenkel, in such a manner that if one set belongs to another then the first must necessarily come before the second in the succession, hence excluding the possibility of a set belonging to itself. To demonstrate that the addition of this new axiom to the others did not produce contradictions, von Neumann introduced a method of demonstration, called the method of inner models, which later became an essential instrument in set theory.
Zermelo and Fraenkel's axiom of foundation established that every set be constructed how?
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The answer: from the bottom up in an ordered succession of steps

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A novelty shop called Au Bon Marche had been founded in Paris in 1838 to sell lace, ribbons, sheets, mattresses, buttons, umbrellas and other assorted goods. It originally had four departments, twelve employees, and a floor space of three hundred meters. The entrepreneur Aristide Boucicaut became a partner in 1852, and changed the marketing plan, instituting fixed prices and guarantees that allowed exchanges and refunds, advertising, and a much wider variety of merchandise. The annual income of the store increased from 500,000 francs in 1852 to five million in 1860. In 1869 he built much larger building at 24 rue de Sevres on the Left Bank, and enlarged the store again in 1872, with help from the engineering firm of Gustave Eiffel, creator of the Eiffel Tower. The income rose from twenty million francs in 1870 to 72 million at the time of the Boucicaut's death in 1877. The floor space had increased from three hundred square meters in 1838 to fifty thousand, and the number of employees had increased from twelve in 1838 to 1788 in 1879. Boucicaut was famous for his marketing innovations; a reading room for husbands while their wives shopped; extensive newspaper advertising; entertainment for children; and six million catalogs sent out to customers. By 1880 half the employees were women; unmarried women employees lived in dormitories on the upper floors.
What engineering company helped the store expand in 1872
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The answer: Gustave Eiffel

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Cubism began between 1907 and 1911. Pablo Picasso's 1907 painting Les Demoiselles d'Avignon has often been considered a proto-Cubist work. Georges Braque's 1908 Houses at L'Estaque (and related works) prompted the critic Louis Vauxcelles to refer to bizarreries cubiques (cubic oddities). Gertrude Stein referred to landscapes made by Picasso in 1909, such as Reservoir at Horta de Ebro, as the first Cubist paintings. The first organized group exhibition by Cubists took place at the Salon des Independants in Paris during the spring of 1911 in a room called 'Salle 41'; it included works by Jean Metzinger, Albert Gleizes, Fernand Leger, Robert Delaunay and Henri Le Fauconnier, yet no works by Picasso or Braque were exhibited.
In the spring of what year did the first organized exhibition by cubist appear?
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The answer: 1911

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The single "Killer Queen" from Sheer Heart Attack reached number two on the British charts, and became their first US hit, reaching number 12 on the Billboard Hot 100. It combines camp, vaudeville, and British music hall with May's guitar virtuosity. The album's second single, "Now I'm Here", a more traditional hard rock composition, was a number eleven hit in Britain, while the high speed rocker "Stone Cold Crazy" featuring May's uptempo riffs is a precursor to speed metal. In recent years, the album has received acclaim from music publications: In 2006, Classic Rock ranked it number 28 in "The 100 Greatest British Rock Albums Ever", and in 2007, Mojo ranked it No.88 in "The 100 Records That Changed the World". It is also the second of three Queen albums to feature in the book 1001 Albums You Must Hear Before You Die.
What music style was found along with camp and vaudeville on the song Killer Queen?
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The answer:
British music hall