Problem: Raleigh, North Carolina:

The region also experiences occasional periods of drought, during which the city sometimes has restricted water use by residents. During the late summer and early fall, Raleigh can experience hurricanes. In 1996, Hurricane Fran caused severe damage in the Raleigh area, mostly from falling trees. The most recent hurricane to have a considerable effect on the area was Isabel in 2003. Tornadoes also have on occasion affected the city of Raleigh most notably the November 28, 1988 tornado which occurred in the early morning hours and rated an F4 on the Fujita Tornado Scale and affected Northwestern portions of the city. Also the April 16, 2011 F3 Tornado which affected portions of downtown and North east Raleigh and the suburb of Holly Springs.

What hurricane hit in 2004?
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A: unanswerable


Problem: Starting in the mid-1990s, Valencia, formerly an industrial centre, saw rapid development that expanded its cultural and touristic possibilities, and transformed it into a newly vibrant city. Many local landmarks were restored, including the ancient Towers of the medieval city (Serrano Towers and Quart Towers), and the San Miguel de los Reyes monastery, which now holds a conservation library. Whole sections of the old city, for example the Carmen Quarter, have been extensively renovated. The Paseo Marítimo, a 4 km (2 mi) long palm tree-lined promenade was constructed along the beaches of the north side of the port (Playa Las Arenas, Playa Cabañal and Playa de la Malvarrosa).
How long is the Paseo Maritimo?
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Answer: 4 km (2 mi)


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Cuban immigrants in the 1960s brought the Cuban sandwich, medianoche, Cuban espresso, and croquetas, all of which have grown in popularity to all Miamians, and have become symbols of the city's varied cuisine. Today, these are part of the local culture, and can be found throughout the city in window cafés, particularly outside of supermarkets and restaurants. Restaurants such as Versailles restaurant in Little Havana is a landmark eatery of Miami. Located on the Atlantic Ocean, and with a long history as a seaport, Miami is also known for its seafood, with many seafood restaurants located along the Miami River, and in and around Biscayne Bay. Miami is also the home of restaurant chains such as Burger King, Tony Roma's and Benihana.
What river is Miami adjacent to?
A: unanswerable


Context and question: The Republic of Letters was the sum of a number of Enlightenment ideals: an egalitarian realm governed by knowledge that could act across political boundaries and rival state power. It was a forum that supported "free public examination of questions regarding religion or legislation". Immanuel Kant considered written communication essential to his conception of the public sphere; once everyone was a part of the "reading public", then society could be said to be enlightened. The people who participated in the Republic of Letters, such as Diderot and Voltaire, are frequently known today as important Enlightenment figures. Indeed, the men who wrote Diderot's Encyclopédie arguably formed a microcosm of the larger "republic".
What did the Republic of Letters support?
Answer: free public examination of questions regarding religion or legislation


Question: All the electromagnetic motors, and that includes the types mentioned here derive the torque from the vector product of the interacting fields. For calculating the torque it is necessary to know the fields in the air gap . Once these have been established by mathematical analysis using FEA or other tools the torque may be calculated as the integral of all the vectors of force multiplied by the radius of each vector. The current flowing in the winding is producing the fields and for a motor using a magnetic material the field is not linearly proportional to the current. This makes the calculation difficult but a computer can do the many calculations needed.
Is there an answer to this question: What is the formulia to determine torque?

Answer: the integral of all the vectors of force multiplied by the radius of each vector


QUES: With nitrides containing aluminium, most often AlGaN and AlGaInN, even shorter wavelengths are achievable. Ultraviolet LEDs in a range of wavelengths are becoming available on the market. Near-UV emitters at wavelengths around 375–395 nm are already cheap and often encountered, for example, as black light lamp replacements for inspection of anti-counterfeiting UV watermarks in some documents and paper currencies. Shorter-wavelength diodes, while substantially more expensive, are commercially available for wavelengths down to 240 nm. As the photosensitivity of microorganisms approximately matches the absorption spectrum of DNA, with a peak at about 260 nm, UV LED emitting at 250–270 nm are to be expected in prospective disinfection and sterilization devices. Recent research has shown that commercially available UVA LEDs (365 nm) are already effective disinfection and sterilization devices. UV-C wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm).

What is the range of wavelengths for cheap UV LEDs?
What is the answer?
ANS:
375–395 nm