input question: I know that the answer to the question "What subject is Free to Choose about?" is in "Hayek is widely recognised for having introduced the time dimension to the equilibrium construction and for his key role in helping inspire the fields of growth theory, information economics, and the theory of spontaneous order. The "informal" economics presented in Milton Friedman's massively influential popular work Free to Choose (1980), is explicitly Hayekian in its account of the price system as a system for transmitting and co-ordinating knowledge. This can be explained by the fact that Friedman taught Hayek's famous paper "The Use of Knowledge in Society" (1945) in his graduate seminars.". Can you tell me what it is????
output answer: "informal" economics

I know that the answer to the question "A mosque is visually important because it is?" is in "Encompasses both secular and religious styles, the design and style made by Muslims and their construction of buildings and structures in Islamic culture included the architectural types: the Mosque, the Tomb, the Palace and the Fort. Perhaps the most important expression of Islamic art is architecture, particularly that of the mosque. Through Islamic architecture, effects of varying cultures within Islamic civilization can be illustrated. Generally, the use of Islamic geometric patterns and foliage based arabesques were striking. There was also the use of decorative calligraphy instead of pictures which were haram (forbidden) in mosque architecture. Note that in secular architecture, human and animal representation was indeed present.". Can you tell me what it is?
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Answer: the most important expression of Islamic art

Q: I know that the answer to the question "Eduard Ahren's works were based on Orthography, culminating in the production of?" is in "Modern Estonian orthography is based on the Newer Orthography created by Eduard Ahrens in the second half of the 19th century based on Finnish orthography. The Older Orthography it replaced was created in the 17th century by Bengt Gottfried Forselius and Johann Hornung based on standard German orthography. Earlier writing in Estonian had by and large used an ad hoc orthography based on Latin and Middle Low German orthography. Some influences of the standard German orthography for example, writing 'W'/'w' instead of 'V'/'v' persisted well into the 1930s.". Can you tell me what it is?
A: Newer Orthography

Question: I know that the answer to the question "What is the system?" is in "Mexico City is served by the Sistema de Transporte Colectivo, a 225.9 km (140 mi) metro system, which is the largest in Latin America. The first portions were opened in 1969 and it has expanded to 12 lines with 195 stations. The metro is one of the busiest in the world transporting approximately 4.5 million people every day, surpassed only by subway lines in Moscow (7.5 million), Tokyo (5.9 million), and New York City (5.1 million). It is heavily subsidized, and has some of the lowest fares in the world, each trip costing 5.00 pesos from 05:00 am to midnight. Several stations display pre-Columbian artifacts and architecture that were discovered during the metro's construction.[citation needed] However, the metro covers less than half of the total urban area. The Metro stations are also differentiated by the use of icons and glyphs which were proposed for people who could not read. The specific icons were developed based on historical (characters, sites, pre-Hispanic motifs), linguistic, symbolic (glyphs) or location references and has being emulated in further transportations alternatives in the City and in other Mexican cities. Mexico City is the only city in the world to use the icon reference and has become a popular culture trademark for the city.". Can you tell me what it is?
Answer: Sistema de Transporte Colectivo

[Q]: I know that the answer to the question "An English mechanical engineer and polymath considered to be father of the computer had a realization when?" is in "Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer. Considered the "father of the computer", he conceptualized and invented the first mechanical computer in the early 19th century. After working on his revolutionary difference engine, designed to aid in navigational calculations, in 1833 he realized that a much more general design, an Analytical Engine, was possible. The input of programs and data was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. The Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.". Can you tell me what it is?
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[A]: 1833

Problem: Given the question: I know that the answer to the question "What pattern is used to create the streets in Philadelphia?" is in "Philadelphia's central city was created in the 17th century following the plan by William Penn's surveyor Thomas Holme. Center City is structured with long straight streets running east-west and north-south forming a grid pattern. The original city plan was designed to allow for easy travel and to keep residences separated by open space that would help prevent the spread of fire. The Delaware River and Schuylkill Rivers served as early boundaries between which the city's early street plan was kept within. In addition, Penn planned the creation of five public parks in the city which were renamed in 1824 (in parenthesis): Centre Square, North East Publick Square (Franklin Square), Northwest Square (Logan Square), Southwest Square (Rittenhouse Square), and Southeast Square (Washington Square). Center City has grown into the second-most populated downtown area in the United States, after Midtown Manhattan in New York City, with an estimated 183,240 residents in 2015.". Can you tell me what it is?
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The answer is:
long straight streets running east-west and north-south