Problem: A cappella:

In July 1943, as a result of the American Federation of Musicians boycott of US recording studios, the a cappella vocal group The Song Spinners had a best-seller with "Comin' In On A Wing And A Prayer". In the 1950s several recording groups, notably The Hi-Los and the Four Freshmen, introduced complex jazz harmonies to a cappella performances. The King's Singers are credited with promoting interest in small-group a cappella performances in the 1960s. In 1983 an a cappella group known as The Flying Pickets had a Christmas 'number one' in the UK with a cover of Yazoo's (known in the US as Yaz) "Only You". A cappella music attained renewed prominence from the late 1980s onward, spurred by the success of Top 40 recordings by artists such as The Manhattan Transfer, Bobby McFerrin, Huey Lewis and the News, All-4-One, The Nylons, Backstreet Boys and Boyz II Men.[citation needed]

In 1983 what did The King's Singers promote?
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A: unanswerable


Problem: In 2010, the literacy rate of Liberia was estimated at 60.8% (64.8% for males and 56.8% for females). In some areas primary and secondary education is free and compulsory from the ages of 6 to 16, though enforcement of attendance is lax. In other areas children are required to pay a tuition fee to attend school. On average, children attain 10 years of education (11 for boys and 8 for girls). The country's education sector is hampered by inadequate schools and supplies, as well as a lack of qualified teachers.
For how many years do children play sports on average?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In the early 1980s, rapidly rising oil revenues enabled the government to finance large-scale development projects with GDP growth averaging 5% annually, one of the highest rates in Africa. The government has mortgaged a substantial portion of its petroleum earnings, contributing to a shortage of revenues. January 12, 1994 devaluation of Franc Zone currencies by 50% resulted in inflation of 46% in 1994, but inflation has subsided since.
What did income from petroleum allow the government to fund in the early '80s?
A: large-scale development projects


Context and question: Charles Town was a hub of the deerskin trade, the basis of its early economy. Trade alliances with the Cherokee and Creek nations insured a steady supply of deer hides. Between 1699 and 1715, colonists exported an average of 54,000 deer skins annually to Europe through Charles Town. Between 1739 and 1761, the height of the deerskin trade era, an estimated 500,000 to 1,250,000 deer were slaughtered. During the same period, Charles Town records show an export of 5,239,350 pounds of deer skins. Deer skins were used in the production of men's fashionable and practical buckskin pantaloons, gloves, and book bindings.
What was the average amount of deer skins  that Charles Town exported to Europe between 1699 to 1715? 
Answer: 54,000


Question: The spectrum emitted by a blackbody radiator at temperatures of incandescent bulbs does not match the sensitivity characteristics of the human eye; the light emitted does not appear white, and most is not in the range of wavelengths at which the eye is most sensitive. Tungsten filaments radiate mostly infrared radiation at temperatures where they remain solid – below 3,695 K (3,422 °C; 6,191 °F). Donald L. Klipstein explains it this way: "An ideal thermal radiator produces visible light most efficiently at temperatures around 6,300 °C (6,600 K; 11,400 °F). Even at this high temperature, a lot of the radiation is either infrared or ultraviolet, and the theoretical luminous efficacy (LER) is 95 lumens per watt." No known material can be used as a filament at this ideal temperature, which is hotter than the sun's surface. An upper limit for incandescent lamp luminous efficacy (LER) is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point.
Is there an answer to this question: What is the lower limit for LER of an incandescent lamp?

Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
According to the apocryphal Gospel of James, Mary was the daughter of Saint Joachim and Saint Anne. Before Mary's conception, Anne had been barren and was far advanced in years. Mary was given to service as a consecrated virgin in the Temple in Jerusalem when she was three years old, much like Hannah took Samuel to the Tabernacle as recorded in the Old Testament. Some apocryphal accounts state that at the time of her betrothal to Joseph, Mary was 12–14 years old, and he was thirty years old, but such accounts are unreliable.
Where was Saint Anne consecrated as a virgin?
A:
unanswerable