This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
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Question: Before World War II, Oklahoma City developed major stockyards, attracting jobs and revenue formerly in Chicago and Omaha, Nebraska. With the 1928 discovery of oil within the city limits (including under the State Capitol), Oklahoma City became a major center of oil production. Post-war growth accompanied the construction of the Interstate Highway System, which made Oklahoma City a major interchange as the convergence of I-35, I-40 and I-44. It was also aided by federal development of Tinker Air Force Base.

Answer: When was oil discovered in the city limits?


Question: The Continental Army was created on 14 June 1775 by the Continental Congress as a unified army for the colonies to fight Great Britain, with George Washington appointed as its commander. The army was initially led by men who had served in the British Army or colonial militias and who brought much of British military heritage with them. As the Revolutionary War progressed, French aid, resources, and military thinking influenced the new army. A number of European soldiers came on their own to help, such as Friedrich Wilhelm von Steuben, who taught the army Prussian tactics and organizational skills.

Answer: When was the Continental Army created?


Question: Greece attracts more than 16 million tourists each year, thus contributing 18.2% to the nation's GDP in 2008 according to an OECD report. The same survey showed that the average tourist expenditure while in Greece was $1,073, ranking Greece 10th in the world. The number of jobs directly or indirectly related to the tourism sector were 840,000 in 2008 and represented 19% of the country's total labor force. In 2009, Greece welcomed over 19.3 million tourists, a major increase from the 17.7 million tourists the country welcomed in 2008.

Answer:
How many millions of tourists does Greece attract each year?