Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
During the 19th century, an important producer of art was the Academia de San Carlos (San Carlos Art Academy), founded during colonial times, and which later became the Escuela Nacional de Artes Plásticas (the National School of Arts) including painting, sculpture and graphic design, one of UNAM's art schools. Many of the works produced by the students and faculty of that time are now displayed in the Museo Nacional de San Carlos (National Museum of San Carlos). One of the students, José María Velasco, is considered one of the greatest Mexican landscape painters of the 19th century. Porfirio Díaz's regime sponsored arts, especially those that followed the French school. Popular arts in the form of cartoons and illustrations flourished, e.g. those of José Guadalupe Posada and Manuel Manilla. The permanent collection of the San Carlos Museum also includes paintings by European masters such as Rembrandt, Velázquez, Murillo, and Rubens.
Where does most of the artwork produced as the Academia de San Carlos get featured? 
A: Museo Nacional de San Carlos

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
There are many styles of mandolin, but four are common, the Neapolitan or round-backed mandolin, the carved-top mandolin and the flat-backed mandolin. The round-back has a deep bottom, constructed of strips of wood, glued together into a bowl. The carved-top or arch-top mandolin has a much shallower, arched back, and an arched top—both carved out of wood. The flat-backed mandolin uses thin sheets of wood for the body, braced on the inside for strength in a similar manner to a guitar. Each style of instrument has its own sound quality and is associated with particular forms of music. Neapolitan mandolins feature prominently in European classical music and traditional music. Carved-top instruments are common in American folk music and bluegrass music. Flat-backed instruments are commonly used in Irish, British and Brazilian folk music. Some modern Brazilian instruments feature an extra fifth course tuned a fifth lower than the standard fourth course.
Which mandolin is uncommon in American Folk music and blue grass music?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In his book The Crucifixion of Jesus, physician and forensic pathologist Frederick Zugibe studied the likely circumstances of the death of Jesus in great detail. Zugibe carried out a number of experiments over several years to test his theories while he was a medical examiner. These studies included experiments in which volunteers with specific weights were hanging at specific angles and the amount of pull on each hand was measured, in cases where the feet were also secured or not. In these cases the amount of pull and the corresponding pain was found to be significant.
What book was written by volunteers?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The fighter aircraft of the USAF are small, fast, and maneuverable military aircraft primarily used for air-to-air combat. Many of these fighters have secondary ground-attack capabilities, and some are dual-roled as fighter-bombers (e.g., the F-16 Fighting Falcon); the term "fighter" is also sometimes used colloquially for dedicated ground-attack aircraft. Other missions include interception of bombers and other fighters, reconnaissance, and patrol. The F-16 is currently used by the USAF Air Demonstration squadron, the Thunderbirds, while a small number of both man-rated and non-man-rated F-4 Phantom II are retained as QF-4 aircraft for use as Full Scale Aerial Targets (FSAT) or as part of the USAF Heritage Flight program. These extant QF-4 aircraft are being replaced in the FSAT role by early model F-16 aircraft converted to QF-16 configuration. The USAF has 2,025 fighters in service as of September 2012.
What aircraft is used by the US Air Demonstration group The Thunderbirds?
A:
F-16