Problem: Electric motor:

A major turning point in the development of DC machines took place in 1864, when Antonio Pacinotti described for the first time the ring armature with its symmetrically grouped coils closed upon themselves and connected to the bars of a commutator, the brushes of which delivered practically non-fluctuating current. The first commercially successful DC motors followed the invention by Zénobe Gramme who, in 1871, reinvented Pacinotti's design. In 1873, Gramme showed that his dynamo could be used as a motor, which he demonstrated to great effect at exhibitions in Vienna and Philadelphia by connecting two such DC motors at a distance of up to 2 km away from each other, one as a generator. (See also 1873 : l'expérience décisive [Decisive Workaround] .)

Besides a motor, what did Gramme use the other device for?
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A: generator


Problem: In the fall of 1985, Gorbachev continued to bring younger and more energetic men into government. On September 27, Nikolai Ryzhkov replaced 79-year-old Nikolai Tikhonov as Chairman of the Council of Ministers, effectively the Soviet prime minister, and on October 14, Nikolai Talyzin replaced Nikolai Baibakov as chairman of the State Planning Committee (GOSPLAN). At the next Central Committee meeting on October 15, Tikhonov retired from the Politburo and Talyzin became a candidate. Finally, on December 23, 1985, Gorbachev appointed Yeltsin First Secretary of the Moscow Communist Party replacing Viktor Grishin.
How old was Tikhonov when he stopped being Chairman?
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Answer: 79-year-old


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University and director of its Atmosphere and Energy Program says producing all new energy with wind power, solar power, and hydropower by 2030 is feasible and existing energy supply arrangements could be replaced by 2050. Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic". Jacobson says that energy costs with a wind, solar, water system should be similar to today's energy costs.
Who stated that energy costs with a wind, solar, water system should not be similar to today's energy costs?
A: unanswerable


Context and question: The native language of Germans is German, a West Germanic language, related to and classified alongside English and Dutch, and sharing many similarities with the North Germanic and Scandinavian languages. Spoken by approximately 100 million native speakers, German is one of the world's major languages and the most widely spoken first language in the European Union. German has been replaced by English as the dominant language of science-related Nobel Prize laureates during the second half of the 20th century. It was a lingua franca in the Holy Roman Empire.
What languages is German related to?
Answer: English and Dutch


Question: Under the Capetian dynasty France slowly began to expand its authority over the nobility, growing out of the Île-de-France to exert control over more of the country in the 11th and 12th centuries. They faced a powerful rival in the Dukes of Normandy, who in 1066 under William the Conqueror (duke 1035–1087), conquered England (r. 1066–87) and created a cross-channel empire that lasted, in various forms, throughout the rest of the Middle Ages. Normans also settled in Sicily and southern Italy, when Robert Guiscard (d. 1085) landed there in 1059 and established a duchy that later became the Kingdom of Sicily. Under the Angevin dynasty of Henry II (r. 1154–89) and his son Richard I (r. 1189–99), the kings of England ruled over England and large areas of France,[W] brought to the family by Henry II's marriage to Eleanor of Aquitaine (d. 1204), heiress to much of southern France.[X] Richard's younger brother John (r. 1199–1216) lost Normandy and the rest of the northern French possessions in 1204 to the French King Philip II Augustus (r. 1180–1223). This led to dissension among the English nobility, while John's financial exactions to pay for his unsuccessful attempts to regain Normandy led in 1215 to Magna Carta, a charter that confirmed the rights and privileges of free men in England. Under Henry III (r. 1216–72), John's son, further concessions were made to the nobility, and royal power was diminished. The French monarchy continued to make gains against the nobility during the late 12th and 13th centuries, bringing more territories within the kingdom under their personal rule and centralising the royal administration. Under Louis IX (r. 1226–70), royal prestige rose to new heights as Louis served as a mediator for most of Europe.[Y]
Is there an answer to this question: To what dynasty did Henry II belong?

Answer: Angevin


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Nanjing first became a state capital in 229 AD, when the state of Eastern Wu founded by Sun Quan during the Three Kingdoms period relocated its capital to Jianye (建業), the city extended on the basis of Jinling Yi in 211 AD. Although conquered by the Western Jin dynasty in 280, Nanjing and its neighbouring areas had been well cultivated and developed into one of the commercial, cultural and political centers of China during the rule of East Wu. This city would soon play a vital role in the following centuries.
When was Nanjing extended?
A:
211 AD