Problem: Question: "Why were Sturgeon and the other DC motor inventors unsuccessful?" Context: "The first commutator DC electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832. Following Sturgeon's work, a commutator-type direct-current electric motor made with the intention of commercial use was built by the American inventor Thomas Davenport, which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press. Due to the high cost of primary battery power, the motors were commercially unsuccessful and Davenport went bankrupt. Several inventors followed Sturgeon in the development of DC motors but all encountered the same battery power cost issues. No electricity distribution had been developed at the time. Like Sturgeon's motor, there was no practical commercial market for these motors." Answer:

A: there was no practical commercial market for these motors

Problem: Question: "A commission investigating the existence of a protocol was led by?" Context: "For decades, it was the official policy of the Soviet Union to deny the existence of the secret protocol to the SovietGerman Pact. At the behest of Mikhail Gorbachev, Alexander Nikolaevich Yakovlev headed a commission investigating the existence of such a protocol. In December 1989, the commission concluded that the protocol had existed and revealed its findings to the Congress of People's Deputies of the Soviet Union. As a result, the Congress passed the declaration confirming the existence of the secret protocols, condemning and denouncing them. Both successor-states of the pact parties have declared the secret protocols to be invalid from the moment they were signed. The Federal Republic of Germany declared this on September 1, 1989 and the Soviet Union on December 24, 1989, following an examination of the microfilmed copy of the German originals." Answer:

A: Alexander Nikolaevich Yakovlev

Problem: Question: "What was King's College's name changed to?" Context: "The trial in Manhattan of John Peter Zenger in 1735 helped to establish the freedom of the press in North America. In 1754, Columbia University was founded under charter by King George II as King's College in Lower Manhattan. The Stamp Act Congress met in New York in October 1765 as the Sons of Liberty organized in the city, skirmishing over the next ten years with British troops stationed there." Answer:

A: Columbia University

Problem: Question: "Most modern Parisian Jews are from?" Context: "During the Middle Ages, Paris was a center of Jewish learning with famous Talmudic scholars, such as Yechiel of Paris who took part in the Disputation of Paris between Christian and Jewish intellectuals. The Parisian Jewish community was victim of persecution, alternating expulsions and returns, until France became the first country in Europe to emancipate its Jewish population during the French Revolution. Although 75% of the Jewish population in France survived the Holocaust during World War II, half the city's Jewish population perished in Nazi concentration camps, while some others fled abroad. A large migration of North Africa Sephardic Jews settled Paris in the 1960s, and represent most of the Paris Jewish community today. There are currently 83 synagogues in the city; The Marais-quarter Agoudas Hakehilos Synagogue, built in 1913 by architect Hector Guimard, is a Paris landmark." Answer:

A:
North Africa