Problem: Gramophone record:

Eventually, when it was more common for electric recordings to be played back electrically in the 1930s and 1940s, the overall tone was much like listening to a radio of the era. Magnetic pickups became more common and were better designed as time went on, making it possible to improve the damping of spurious resonances. Crystal pickups were also introduced as lower cost alternatives. The dynamic or moving coil microphone was introduced around 1930 and the velocity or ribbon microphone in 1932. Both of these high quality microphones became widespread in motion picture, radio, recording, and public address applications.

When would you have first found the moving coil microphone?
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A: around 1930

Problem: Canadian bitumen does not differ substantially from oils such as Venezuelan extra-heavy and Mexican heavy oil in chemical composition, and the real difficulty is moving the extremely viscous bitumen through oil pipelines to the refinery. Many modern oil refineries are extremely sophisticated and can process non-upgraded bitumen directly into products such as gasoline, diesel fuel, and refined asphalt without any preprocessing. This is particularly common in areas such as the US Gulf coast, where refineries were designed to process Venezuelan and Mexican oil, and in areas such as the US Midwest where refineries were rebuilt to process heavy oil as domestic light oil production declined. Given the choice, such heavy oil refineries usually prefer to buy bitumen rather than synthetic oil because the cost is lower, and in some cases because they prefer to produce more diesel fuel and less gasoline. By 2015 Canadian production and exports of non-upgraded bitumen exceeded that of synthetic crude oil at over 1.3 million barrels (21010^3 m3) per day, of which about 65% was exported to the United States.
Other than Mexican extra-heavy oil, what type of oil does Canadian bitumen not differ greatly from?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
However Cornelius Clifford places his birth no earlier than 296 and no later than 298, based on the fact that Athanasius indicates no first hand recollection of the Maximian persecution of 303, which he suggests Athanasius would have remembered if he had been ten years old at the time. Secondly, the Festal Epistles state that the Arians had accused Athanasius, among other charges, of not having yet attained the canonical age (30) and thus could not have been properly ordained as Patriarch of Alexandria in 328. The accusation must have seemed plausible. The Orthodox Church places his year of birth around 297.
When was Cornelius Clifford ordained as Patriarch of Alexandria?
A: unanswerable

Context and question: The Allied disaster at Austerlitz significantly shook the faith of Emperor Francis in the British-led war effort. France and Austria agreed to an armistice immediately and the Treaty of Pressburg followed shortly after on 26 December. Pressburg took Austria out of both the war and the Coalition while reinforcing the earlier treaties of Campo Formio and of Luneville between the two powers. The treaty confirmed the Austrian loss of lands to France in Italy and Bavaria, and lands in Germany to Napoleon's German allies. It also imposed an indemnity of 40 million francs on the defeated Habsburgs and allowed the fleeing Russian troops free passage through hostile territories and back to their home soil. Napoleon went on to say, "The battle of Austerlitz is the finest of all I have fought." Frank McLynn suggests that Napoleon was so successful at Austerlitz that he lost touch with reality, and what used to be French foreign policy became a "personal Napoleonic one". Vincent Cronin disagrees, stating that Napoleon was not overly ambitious for himself, "he embodied the ambitions of thirty million Frenchmen".
What was the name of the treaty signed by France and Austria on 26 December?
Answer: the Treaty of Pressburg

Question: The three brothersRurik, Sineus, and Truvorestablished themselves in Novgorod, Beloozero, and Izborsk, respectively. Two of the brothers died, and Rurik became the sole ruler of the territory and progenitor of the Rurik Dynasty. A short time later, two of Rurik's men, Askold and Dir, asked him for permission to go to Tsargrad (Constantinople). On their way south, they discovered "a small city on a hill," Kiev, captured it and the surrounding country from the Khazars, populated the region with more Varangians, and "established their dominion over the country of the Polyanians."
Is there an answer to this question: What was the name of the large city on the hill that was discovered by Rurik's men?

Answer: unanswerable

Question: The kingdom is mentioned in the Periplus of the Erythraean Sea as an important market place for ivory, which was exported throughout the ancient world. Aksum was at the time ruled by Zoskales, who also governed the port of Adulis. The Aksumite rulers facilitated trade by minting their own Aksumite currency. The state also established its hegemony over the declining Kingdom of Kush and regularly entered the politics of the kingdoms on the Arabian peninsula, eventually extending its rule over the region with the conquest of the Himyarite Kingdom.
Is there an answer to this question: What product did the Kingdom of Kush export?

Answer:
unanswerable