Problem: Infrared:

Infrared reflectography (fr; it; es), as called by art conservators, can be applied to paintings to reveal underlying layers in a completely non-destructive manner, in particular the underdrawing or outline drawn by the artist as a guide. This often reveals the artist's use of carbon black, which shows up well in reflectograms, as long as it has not also been used in the ground underlying the whole painting. Art conservators are looking to see whether the visible layers of paint differ from the underdrawing or layers in between such alterations are called pentimenti when made by the original artist. This is very useful information in deciding whether a painting is the prime version by the original artist or a copy, and whether it has been altered by over-enthusiastic restoration work. In general, the more pentimenti the more likely a painting is to be the prime version. It also gives useful insights into working practices.

What technique is used in art to examine underlying layers of a painting without damaging it?
---
A: Infrared reflectography

Problem: In Argentina, the most representative Carnival performed is the so-called Murga, although other famous Carnivals, more like Brazil's, are held in Argentine Mesopotamia and the North-East. Gualeguaychu in the east of Entre Rios province is the most important Carnival city and has one of the largest parades. It adopts a musical background similar to Brazilian or Uruguayan Carnival. Corrientes is another city with a Carnival tradition. Chamame is a popular musical style. In all major cities and many towns throughout the country, Carnival is celebrated.
What city in the east of Entre Rios province is considered the most important one for the Carnival?
---
Answer: Gualeguaychu

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Dell traces its origins to 1984, when Michael Dell created Dell Computer Corporation, which at the time did business as PC's Limited, while a student of the University of Texas at Austin. The dorm-room headquartered company sold IBM PC-compatible computers built from stock components. Dell dropped out of school to focus full-time on his fledgling business, after getting $1,000 in expansion-capital from his family. In 1985, the company produced the first computer of its own design, the Turbo PC, which sold for $795. PC's Limited advertised its systems in national computer magazines for sale directly to consumers and custom assembled each ordered unit according to a selection of options. The company grossed more than $73 million in its first year of operation.
When did Michael Dell found his company?
A: 1984

Context and question: The moratorium ended on January 17, 1977 with the shooting of Gary Gilmore by firing squad in Utah. The first use of the electric chair after the moratorium was the electrocution of John Spenkelink in Florida on May 25, 1979. The first use of the gas chamber after the moratorium was the gassing of Jesse Bishop in Nevada on October 22, 1979. The first use of the gallows after the moratorium was the hanging of Westley Allan Dodd in Washington on January 5, 1993. The first use of lethal injection was on December 7, 1982, when Charles Brooks, Jr., was executed in Texas.
On what date was John Spenkelink executed?
Answer: May 25, 1979

Question: The five Great Lakes are located in the north-central portion of the country, four of them forming part of the border with Canada, only Lake Michigan situated entirely within United States. The southeast United States contain subtropical forests and, near the gulf coast, mangrove wetlands, especially in Florida. West of the Appalachians lies the Mississippi River basin and two large eastern tributaries, the Ohio River and the Tennessee River. The Ohio and Tennessee Valleys and the Midwest consist largely of rolling hills and productive farmland, stretching south to the Gulf Coast.
Is there an answer to this question: Which section of the US contains tropical forests and mangrove wetlands?

Answer: unanswerable

Question: In November 1790, Francois-Louis-Thibault de Menonville, a member of the National Assembly of France, wrote to Burke, praising Reflections and requesting more "very refreshing mental food" that he could publish. This Burke did in April 1791 when he published A Letter to a Member of the National Assembly. Burke called for external forces to reverse the revolution and included an attack on the late French philosopher Jean-Jacques Rousseau, as being the subject of a personality cult that had developed in revolutionary France. Although Burke conceded that Rousseau sometimes showed "a considerable insight into human nature" he mostly was critical. Although he did not meet Rousseau on his visit to Britain in 17667 Burke was a friend of David Hume, with whom Rousseau had stayed. Burke said Rousseau "entertained no principle either to influence of his heart, or to guide his understandingbut vanity"which he "was possessed to a degree little short of madness". He also cited Rousseau's Confessions as evidence that Rousseau had a life of "obscure and vulgar vices" that was not "chequered, or spotted here and there, with virtues, or even distinguished by a single good action". Burke contrasted Rousseau's theory of universal benevolence and his having sent his children to a foundling hospital: "a lover of his kind, but a hater of his kindred".
Is there an answer to this question: What vice-filled book did Hume publish?

Answer:
unanswerable