Problem: Han dynasty:

The armillary sphere, a three-dimensional representation of the movements in the celestial sphere, was invented in Han China by the 1st century BC. Using a water clock, waterwheel and a series of gears, the Court Astronomer Zhang Heng (78139 AD) was able to mechanically rotate his metal-ringed armillary sphere. To address the problem of slowed timekeeping in the pressure head of the inflow water clock, Zhang was the first in China to install an additional tank between the reservoir and inflow vessel. Zhang also invented a seismometer (Houfeng didong yi ) in 132 AD to detect the exact cardinal or ordinal direction of earthquakes from hundreds of kilometers away. This employed an inverted pendulum that, when disturbed by ground tremors, would trigger a set of gears that dropped a metal ball from one of eight dragon mouths (representing all eight directions) into a metal toad's mouth.

What was exchanged from mouth to mouth in the usage of the seismometer?
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A: metal ball

Problem: In 1768 Russian-backed Ukrainian Haidamaks, pursuing Polish confederates, entered Balta, an Ottoman-controlled town on the border of Bessarabia in Ukraine, and massacred its citizens and burned the town to the ground. This action provoked the Ottoman Empire into the Russo-Turkish War of 17681774. The Treaty of Kucuk Kaynarca of 1774 ended the war and provided freedom to worship for the Christian citizens of the Ottoman-controlled provinces of Wallachia and Moldavia. By the late 18th century, a number of defeats in several wars with Russia led some people in the Ottoman Empire to conclude that the reforms of Peter the Great had given the Russians an edge, and the Ottomans would have to keep up with Western technology in order to avoid further defeats.
During what years was the Russo-Turkish war?
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Answer: 17681774

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Sebastian Cabot declares in a handwritten Latin text in his original 1545 map, that the St. John's earned its name when he and his father, the Venetian explorer John Cabot became the first Europeans to sail into the harbour, in the morning of 24 June 1494 (against British and French historians stating 1497), the feast day of Saint John the Baptist. However, the exact locations of Cabot's landfalls are disputed. A series of expeditions to St. John's by Portuguese from the Azores took place in the early 16th century, and by 1540 French, Spanish and Portuguese ships crossed the Atlantic annually to fish the waters off the Avalon Peninsula. In the Basque Country, it is a common belief that the name of St. John's was given by Basque fishermen because the bay of St. John's is very similar to the Bay of Pasaia in the Basque Country, where one of the fishing towns is also called St. John (in Spanish, San Juan, and in Basque, Donibane).
Who did British and French historians claim sailed into St John's harbor in 1494?
A: unanswerable

Context and question: Sociocultural anthropology draws together the principle axes of cultural anthropology and social anthropology. Cultural anthropology is the comparative study of the manifold ways in which people make sense of the world around them, while social anthropology is the study of the relationships among persons and groups. Cultural anthropology is more related to philosophy, literature and the arts (how one's culture affects experience for self and group, contributing to more complete understanding of the people's knowledge, customs, and institutions), while social anthropology is more related to sociology and history. in that it helps develop understanding of social structures, typically of others and other populations (such as minorities, subgroups, dissidents, etc.). There is no hard-and-fast distinction between them, and these categories overlap to a considerable degree.
What kind of distinction is lacking between social and cultural anthropology?
Answer: hard-and-fast

Question: The Napoleonic Wars were the cause of the final dissolution of the Holy Roman Empire, and ultimately the cause for the quest for a German nation state in 19th-century German nationalism. After the Congress of Vienna, Austria and Prussia emerged as two competitors. Austria, trying to remain the dominant power in Central Europe, led the way in the terms of the Congress of Vienna. The Congress of Vienna was essentially conservative, assuring that little would change in Europe and preventing Germany from uniting. These terms came to a sudden halt following the Revolutions of 1848 and the Crimean War in 1856, paving the way for German unification in the 1860s. By the 1820s, large numbers of Jewish German women had intermarried with Christian German men and had converted to Christianity. Jewish German Eduard Lasker was a prominent German nationalist figure who promoted the unification of Germany in the mid-19th century.
Is there an answer to this question: What was one of the main factors that caused the dissolve of the Holy Roman Empire?

Answer: Napoleonic Wars

Problem: Buckingham Palace:

On 15 September 1940, known as the Battle of Britain Day, an RAF pilot, Ray Holmes of No. 504 Squadron RAF rammed a German bomber he believed was going to bomb the Palace. Holmes had run out of ammunition and made the quick decision to ram it. Holmes bailed out. Both aircraft crashed. In fact the Dornier Do 17 bomber was empty. It had already been damaged, two of its crew had been killed and the remainder bailed out. Its pilot, Feldwebel Robert Zehbe, landed, only to die later of wounds suffered during the attack. During the Dornier's descent, it somehow unloaded its bombs, one of which hit the Palace. It then crashed into the forecourt of London Victoria station. The bomber's engine was later exhibited at the Imperial War Museum in London. The British pilot became a King's Messenger after the war, and died at the age of 90 in 2005.

What type of airplane was the German craft Holmes rammed into?
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A:
Dornier Do 17 bomber