Problem: Presbyterianism:

In 1972, the Presbyterian Church of England (PCofE) united with the Congregational Church in England and Wales to form the United Reformed Church (URC). Among the congregations the PCofE brought to the URC were Tunley (Lancashire), Aston Tirrold (Oxfordshire) and John Knox Presbyterian Church, Stepney, London (now part of Stepney Meeting House URC) – these are among the sole survivors today of the English Presbyterian churches of the 17th century. The URC also has a presence in Scotland, mostly of former Congregationalist Churches. Two former Presbyterian congregations, St Columba's, Cambridge (founded in 1879), and St Columba's, Oxford (founded as a chaplaincy by the PCofE and the Church of Scotland in 1908 and as a congregation of the PCofE in 1929), continue as congregations of the URC and university chaplaincies of the Church of Scotland.

In what year was Stepney Meeting House founded?
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A: unanswerable


Problem: In 941, Igor led another major Rus' attack on Constantinople, probably over trading rights again. A navy of 10,000 vessels, including Pecheneg allies, landed on the Bithynian coast and devastated the Asiatic shore of the Bosphorus. The attack was well-timed, perhaps due to intelligence, as the Byzantine fleet was occupied with the Arabs in the Mediterranean, and the bulk of its army was stationed in the east. The Rus’ burned towns, churches, and monasteries, butchering the people and amassing booty. The emperor arranged for a small group of retired ships to be outfitted with Greek fire throwers and sent them out to meet the Rus’, luring them into surrounding the contingent before unleashing the Greek fire. Liutprand of Cremona wrote that "the Rus', seeing the flames, jumped overboard, preferring water to fire. Some sank, weighed down by the weight of their breastplates and helmets; others caught fire." Those captured were beheaded. The ploy dispelled the Rus’ fleet, but their attacks continued into the hinterland as far as Nicomedia, with many atrocities reported as victims were crucified and set up for use as targets. At last a Byzantine army arrived from the Balkans to drive the Rus' back, and a naval contingent reportedly destroyed much of the Rus' fleet on its return voyage (possibly an exaggeration since the Rus' soon mounted another attack). The outcome indicates increased military might by Byzantium since 911, suggesting a shift in the balance of power.
What year did Oleg make peace with Constantinople?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Von Neumann raised the intellectual and mathematical level of economics in several stunning publications. For his model of an expanding economy, von Neumann proved the existence and uniqueness of an equilibrium using his generalization of the Brouwer fixed-point theorem. Von Neumann's model of an expanding economy considered the matrix pencil  A − λB with nonnegative matrices A and B; von Neumann sought probability vectors p and q and a positive number λ that would solve the complementarity equation
How did von Neumann raise the level of economics?
A: several stunning publications


Context and question: The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even arcing if the tunnel segments are not electrically bonded together. The problem was exacerbated because the return current also had a tendency to flow through nearby iron pipes forming the water and gas mains. Some of these, particularly Victorian mains that predated London's underground railways, were not constructed to carry currents and had no adequate electrical bonding between pipe segments. The four-rail system solves the problem. Although the supply has an artificially created earth point, this connection is derived by using resistors which ensures that stray earth currents are kept to manageable levels. Power-only rails can be mounted on strongly insulating ceramic chairs to minimise current leak, but this is not possible for running rails which have to be seated on stronger metal chairs to carry the weight of trains. However, elastomeric rubber pads placed between the rails and chairs can now solve part of the problem by insulating the running rails from the current return should there be a leakage through the running rails.
What danger can return currents cause?
Answer: electrolytic damage


Question: The Dutch written grammar has simplified over the past 100 years: cases are now mainly used for the pronouns, such as ik (I), mij, me (me), mijn (my), wie (who), wiens (whose: masculine or neuter singular), wier (whose: feminine singular; masculine, feminine or neuter plural). Nouns and adjectives are not case inflected (except for the genitive of proper nouns (names): -s, -'s or -'). In the spoken language cases and case inflections had already gradually disappeared from a much earlier date on (probably the 15th century) as in many continental West Germanic dialects.
Is there an answer to this question: Over what span of time have the rules for written Dutch become less complicated?

Answer: 100 years


Problem: Nintendo Entertainment System:

To differentiate Nintendo's new home platform from the early 1980s' common perception of a troubled and shallow video game market, the company freshened its product nomenclature and positioning, and it established a strict product approval and licensing policy. The overall system was referred to as an "Entertainment System" instead of a "video game system", which was centered upon a machine called a "Control Deck" instead of a "console", and which featured software cartridges called "Game Paks" instead of "video games". The 10NES lockout chip system acted as a lock-and-key coupling of each Game Pak and Control Deck, deterring the copying or production of NES games which had not first achieved Nintendo's licensed approval. The packaging of the launch lineup of NES games bore pictures of a very close representation of the actual onscreen graphics of the game, which were of sufficiently recognizable quality on their own. Symbols on the launch games' packaging clearly indicated the genre of the game, in order to reduce consumer confusion. A 'seal of quality' was printed on all appropriately licensed game and accessory packaging. The initial seal stated, "This seal is your assurance that Nintendo has approved and guaranteed the quality of this product". This text was later changed to "Official Nintendo Seal of Quality".

 The seal of quality didn't take on what eventual name?
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A:
unanswerable