Here is a question about this article: The U.S. Eisenhower administration condemned the tripartite invasion, and supported UN resolutions demanding withdrawal and a United Nations Emergency Force (UNEF) to be stationed in Sinai. Nasser commended Eisenhower, stating he played the "greatest and most decisive role" in stopping the "tripartite conspiracy". By the end of December, British and French forces had totally withdrawn from Egyptian territory, while Israel completed its withdrawal in March 1957 and released all Egyptian prisoners of war. As a result of the Suez Crisis, Nasser brought in a set of regulations imposing rigorous requirements for residency and citizenship as well as forced expulsions, mostly affecting British and French nationals and Jews with foreign nationality, as well as some Egyptian Jews.
What is the answer to this question: What military force was brought in to calm the situation?
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So... United Nations Emergency Force


Here is a question about this article: Whitehead and Russell had thought originally that Principia Mathematica would take a year to complete; it ended up taking them ten years. To add insult to injury, when it came time for publication, the three-volume work was so massive (more than 2,000 pages) and its audience so narrow (professional mathematicians) that it was initially published at a loss of 600 pounds, 300 of which was paid by Cambridge University Press, 200 by the Royal Society of London, and 50 apiece by Whitehead and Russell themselves. Despite the initial loss, today there is likely no major academic library in the world which does not hold a copy of Principia Mathematica.
What is the answer to this question: How long did it actually take to complete Principia Mathematica? 
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So... ten years


Here is a question about this article: In late December, Barcelona's appeal to the Court of Arbitration for Sport was unsuccessful and the original transfer ban was reinstated, leaving the club unable to utilise the 2015 winter and summer transfer windows. On 5 January 2015, Zubizareta was sacked by the board after 4 years as director of football. The next month, Barcelona announced the formation of a new Football Area Technical Commission, made up of vice-president Jordi Mestre, board member Javier Bordas, Carles Rexach and Ariedo Braida.
What is the answer to this question: During what year was Barcelona not allowed to use  their transfer windows?
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So...
2015