instruction:
In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
question:
Passage: Albrecht the Elder was 62 or 63 when his panel was painted early in 1490. Barbara's portrait may have been completed soon after, when she would have been around 39. Their son was around 18 and had just completed his apprenticeship with Michael Wolgemut, and would soon leave for Nuremberg to travel as a journeyman painter. The father panel was painted first; for aesthetic reasons Durer may have waited a year or two until his mother looked older.The sitters are presented in three-quarter view before flat, nondescript lacquer-like green backgrounds, which although lushly coloured, are thinly layered. Each has a white ground and light red imprimatura with lead content. The sitter's form and pose echo and in many ways counterbalance each other. Brand Philip draws attention to the similarities of the panels' linear construction, especially the manner in which the folds and lines of their clothing form triangular shapes. The train of Barbara's headdress across her chest corresponds with the opening of Albrecht's fur-lined coat. It was more usual in pendant portraits of this type for the male to be on the left-hand side; the positioning here may be an indication that Durer originally intended his father's panel to stand alone, given that Barbara's was painted some time later.Albrecht the Elder's panel is regarded as the superior of the two works. This may in part be attributed to differing contemporary treatments of male and female portraits; men were allowed more individuality, while female portraits were bound by stereotypes and were not as daring, for example showing evidence of ageing. In either case, the father painting is far more closely detailed, especially in the lining of clothing, which is summary in Barbara's panel, compared to the long seam of her husband's gown. This contrast in detail can also be seen in the treatment of the rosaries, which are given prominence and a glowing red colour in his panel, but are small and relegated in hers.Albrecht the Elder's panel is usually, but not always, thought to be the first of the two to be executed and, if so, is the earliest extant example of his son's painting. In contrast, a number of art historians have noted that his mother's portrait contains bland passages, especially around the eyes and may be a near-contemporary copy of a lost original. Lotte Brand Philip believes the clumsiness in the mother panel indicated that Durer painted it first, as a youthful attempt at portraiture, and that Albrecht the Elder might have later "commissioned" his own portrait to pair with Barbara's. Recent technical examination of the two panels confirms that Barbara's portrait was painted later than her husband's.
answer:
What is the name of the person that completed his apprenticeship with Michael Wolgemut?

question:
Passage: By the 15th century the reach and influence of the Burgundian princes meant that the Low Countries' merchant and banker classes were in the ascendancy. The early to mid-century saw great rises in international trade and domestic wealth, leading to an enormous increase in the demand for art. Artists from the area attracted patronage from the Baltic coast, the north German and Polish regions, the Iberian Peninsula, Italy and the powerful families of England and Scotland. At first, masters had acted as their own dealers, attending fairs where they could also buy frames, panels and pigments. The mid-century saw the development of art dealership as a profession; the activity became purely commercially driven, dominated by the mercantile class.
Burgundian rule created a large class of courtiers and functionaries. Some gained enormous power and commissioned paintings to display their wealth and influence. Civic leaders also commissioned works from major artists, such as Bouts' Justice for Emperor Otto III, van der Weyden's The Justice of Trajan and Herkinbald and David's Justice of Cambyses. Civic commissions were less common and were not as lucrative, but they brought notice to and increased a painter's reputation, as with Memling, whose St John Altarpiece for Bruges' Sint-Janshospitaal brought him additional civic commissions.Wealthy foreign patronage and the development of international trade afforded the established masters the chance to build up workshops with assistants. Although first-rank painters such as Petrus Christus and Hans Memling found patrons among the local nobility, they catered specifically to the large foreign population in Bruges. Painters not only exported goods but also themselves; foreign princes and nobility, striving to emulate the opulence of the Burgundian court, hired painters away from Bruges.
answer:
What were the name of three paintings civic leaders commissioned from major artists?

question:
Passage: Nathan Ellis, a 9-year-old maths prodigy, has just lost his father in a car accident. Nathan is diagnosed with autism early in the film, and his father was the only one who was able to connect normally with him. Although Nathan values his mother, Julie, he shuns any physical contact with her and treats her as more of a caretaker than a parent. Wanting to make sure Nathan isn't distracted from his studies, Julie enrolls him in advanced classes at a new school. There, he comes under the tutelage of teacher Martin, also a math genius, who now suffers from multiple sclerosis. Martin sees himself in Nathan, once a promising young mind in the field of mathematics, who gave it all up once he was diagnosed with his illness.
Seven years later, Martin is preparing Nathan to compete for a place in the International Mathematical Olympiad, a prestigious high school competition consisting of the world's best young mathematicians. This year, it is to be held at Cambridge, after a two-week math camp in Taiwan where the students will study for the test that determines the winners. Nathan fears he's not good enough to qualify but ends up doing well enough to accompany 15 other British teenagers to Taiwan.
Suddenly thrust out of his comfort zone, Nathan finds himself no longer the smartest math whiz in the room, and his social anxieties nearly paralyze his performance. He has trouble reading the social cues of others and flinches at the slightest physical contact with another person. Nathan is paired with a female Chinese student, Zhang Mei, who slowly helps him adjust to his new surroundings and helps him fight through his fears. By the skin of their teeth, Nathan and Zhang make the cut to compete in Cambridge.
answer:
Who comes under the tutelage of a math genius teacher?