Article: Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. Heavy water, which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. François Isaac de Rivaz built the first de Rivaz engine, an internal combustion engine powered by a mixture of hydrogen and oxygen in 1806. Edward Daniel Clarke invented the hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823.

Question: Who was the first to discover deuterium?
Ans: Harold Urey


Article: The public water supply network was completed in 1850, and in 1858 the architects Sebastián Monleón Estellés, Antonino Sancho, and Timoteo Calvo drafted a general expansion project for the city that included demolishing its ancient walls (a second version was printed in 1868). Neither proposed project received final approval, but they did serve as a guide, though not closely followed, for future growth. By 1860 the municipality had 140,416 inhabitants, and beginning in 1866 the ancient city walls were almost entirely demolished to facilitate urban expansion. Electricity was introduced to Valencia in 1882.

Question: What was Valencia's population in 1860?
Ans: 140,416


Article: Raleigh is home to North Carolina State University and is part of the Research Triangle area, together with Durham (home of Duke University) and Chapel Hill (home of the University of North Carolina at Chapel Hill). The "Triangle" nickname originated after the 1959 creation of the Research Triangle Park, located in Durham & Wake Counties partway between the three cities and their universities. The Research Triangle region encompasses the U.S. Census Bureau's Raleigh-Durham-Chapel Hill Combined Statistical Area (CSA), which had an estimated population of 2,037,430 in 2013. The Raleigh Metropolitan Statistical Area (MSA) had an estimated population of 1,214,516 in 2013.

Question: What university is in Raleigh?
Ans: North Carolina State University


Article: The Seljuk Empire soon started to collapse. In the early 12th century, Armenian princes of the Zakarid noble family drove out the Seljuk Turks and established a semi-independent Armenian principality in Northern and Eastern Armenia, known as Zakarid Armenia, which lasted under the patronage of the Georgian Kingdom. The noble family of Orbelians shared control with the Zakarids in various parts of the country, especially in Syunik and Vayots Dzor, while the Armenian family of Hasan-Jalalians controlled provinces of Artsakh and Utik as the Kingdom of Artsakh.

Question: What area did the Hasan-jalalians command?
Ans:
Artsakh and Utik