Problem: Computer:

The tide-predicting machine invented by Sir William Thomson in 1872 was of great utility to navigation in shallow waters. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location.

What did Sir William Thomson's tide-predicting machine use to function?
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A: system of pulleys and wires


Problem: The Republic of the United Provinces lasted until a series of republican revolutions in 1783–1795 created the Batavian Republic. During this period, republican forces took several major cities of the Netherlands. After initially fleeing, the monarchist forces came back with British, Austrian, and Prussian troops and retook the Netherlands. The republican forces fled to France, but then successfully re-invaded alongside the army of the French republic. After the French Republic became the French Empire under Napoleon, the Batavian Republic was replaced by the Napoleonic Kingdom of Holland.
What happened that led to the creation of the French Republic?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In 2013 and 2014, a Russian/Ukrainian hacking ring known as "Rescator" broke into Target Corporation computers in 2013, stealing roughly 40 million credit cards, and then Home Depot computers in 2014, stealing between 53 and 56 million credit card numbers. Warnings were delivered at both corporations, but ignored; physical security breaches using self checkout machines are believed to have played a large role. "The malware utilized is absolutely unsophisticated and uninteresting," says Jim Walter, director of threat intelligence operations at security technology company McAfee – meaning that the heists could have easily been stopped by existing antivirus software had administrators responded to the warnings. The size of the thefts has resulted in major attention from state and Federal United States authorities and the investigation is ongoing.
What machines were involved in the physical security breaches that played a large role in the incident?
A: self checkout machines


Context and question: The Premier League sells its television rights on a collective basis. This is in contrast to some other European Leagues, including La Liga, in which each club sells its rights individually, leading to a much higher share of the total income going to the top few clubs. The money is divided into three parts: half is divided equally between the clubs; one quarter is awarded on a merit basis based on final league position, the top club getting twenty times as much as the bottom club, and equal steps all the way down the table; the final quarter is paid out as facilities fees for games that are shown on television, with the top clubs generally receiving the largest shares of this. The income from overseas rights is divided equally between the twenty clubs.
Do European Leagues sell their television rights per a collective level?
Answer: other European Leagues, including La Liga, in which each club sells its rights individually


Question: Several churches and monasteries were built inside, or close to, the city of Utrecht. The most dominant of these was the Cathedral of Saint Martin, inside the old Roman fortress. The construction of the present Gothic building was begun in 1254 after an earlier romanesque construction had been badly damaged by fire. The choir and transept were finished from 1320 and were followed then by the ambitious Dom tower. The last part to be constructed was the central nave, from 1420. By that time, however, the age of the great cathedrals had come to an end and declining finances prevented the ambitious project from being finished, the construction of the central nave being suspended before the planned flying buttresses could be finished. Besides the cathedral there were four collegiate churches in Utrecht: St. Salvator's Church (demolished in the 16th century), on the Dom square, dating back to the early 8th century. Saint John (Janskerk), originating in 1040; Saint Peter, building started in 1039 and Saint Mary's church building started around 1090 (demolished in the early 19th century, cloister survives). Besides these churches the city housed St. Paul's Abbey, the 15th-century beguinage of St. Nicholas, and a 14th-century chapter house of the Teutonic Knights.
Is there an answer to this question: When was construction completed on the Cathedral of Saint Martin?

Answer: unanswerable


Problem: Group (mathematics):

In the example above, the identity and the rotations constitute a subgroup R = {id, r1, r2, r3}, highlighted in red in the group table above: any two rotations composed are still a rotation, and a rotation can be undone by (i.e. is inverse to) the complementary rotations 270° for 90°, 180° for 180°, and 90° for 270° (note that rotation in the opposite direction is not defined). The subgroup test is a necessary and sufficient condition for a subset H of a group G to be a subgroup: it is sufficient to check that g−1h ∈ H for all elements g, h ∈ H. Knowing the subgroups is important in understanding the group as a whole.d[›]

270 for 180 is an example of what kind of rotation?
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A:
unanswerable