Problem: Light-emitting diode:

The first blue-violet LED using magnesium-doped gallium nitride was made at Stanford University in 1972 by Herb Maruska and Wally Rhines, doctoral students in materials science and engineering. At the time Maruska was on leave from RCA Laboratories, where he collaborated with Jacques Pankove on related work. In 1971, the year after Maruska left for Stanford, his RCA colleagues Pankove and Ed Miller demonstrated the first blue electroluminescence from zinc-doped gallium nitride, though the subsequent device Pankove and Miller built, the first actual gallium nitride light-emitting diode, emitted green light. In 1974 the U.S. Patent Office awarded Maruska, Rhines and Stanford professor David Stevenson a patent for their work in 1972 (U.S. Patent US3819974 A) and today magnesium-doping of gallium nitride continues to be the basis for all commercial blue LEDs and laser diodes. These devices built in the early 1970s had too little light output to be of practical use and research into gallium nitride devices slowed. In August 1989, Cree introduced the first commercially available blue LED based on the indirect bandgap semiconductor, silicon carbide (SiC). SiC LEDs had very low efficiency, no more than about 0.03%, but did emit in the blue portion of the visible light spectrum.[citation needed]

When was the first blue-violet LED developed?
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A: 1972


Problem: Eton is one of ten English HMC schools, commonly referred to as "public schools", regulated by the Public Schools Act of 1868. Following the public school tradition, Eton is a full boarding school, which means all pupils live at the school, and it is one of four such remaining single-sex boys' public schools in the United Kingdom (the others being Harrow, Radley, and Winchester) to continue this practice. Eton has educated 19 British prime ministers and generations of the aristocracy and has been referred to as the chief nurse of England's statesmen. Charging up to £11,478 per term (there are three terms per academic year) in 2014/15, Eton is the sixth most expensive HMC boarding school in the UK.
Which one of the ten English HMC schools is girls only?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Not only that, Austria now found herself estranged with the new developments within the empire itself. Beside the rise of Prussia, Augustus III, although ineffective, could mustered up an army not only from Saxony, but also Poland, considering the elector was also the King of Poland. Bavaria's growing power and independence was also apparent as she had more voices on the path that its army should have taken, and managed to slip out of the war at its own will. Most importantly, with the now somehow-belligerent Hanover united personally under George III of Great Britain, It can amassed a considerable power, even brought Britain in, on the future conflicts. This power dynamic is important to the future and the latter conflicts of the empire. The war also proved that Maria Theresa's reforms were still not enough to compete with Prussia: unlike its enemy, the Austrians went almost bankrupt at the end of war. Hence, she dedicated the next two decades to the consolidation of her administration.
What was the change in the status of Prussia because of the war?
A: Beside the rise of Prussia


Context and question: In the following decades there was a constant battle between the company lobby and the Parliament. The company sought a permanent establishment, while the Parliament would not willingly allow it greater autonomy and so relinquish the opportunity to exploit the company's profits. In 1712, another act renewed the status of the company, though the debts were repaid. By 1720, 15% of British imports were from India, almost all passing through the company, which reasserted the influence of the company lobby. The licence was prolonged until 1766 by yet another act in 1730.
in 1720 what % of  import goods were from India? 
Answer: 15%


Question: In Austria, the Austrian Constitution of 1920 (based on a draft by Hans Kelsen) introduced judicial review of legislative acts for their constitutionality. This function is performed by the Constitutional Court (Verfassungsgerichtshof), which is also charged with the review of administrative acts on whether they violate constitutionally guaranteed rights. Other than that, administrative acts are reviewed by the Administrative Court (Verwaltungsgerichtshof). The Supreme Court (Oberste Gerichtshof (OGH)), stands at the top of Austria's system of "ordinary courts" (ordentliche Gerichte) as the final instance in issues of private law and criminal law.
Is there an answer to this question: What was drafted in 1902?

Answer: unanswerable


Question: The eastern arm shows considerable diversity. In England it is generally long and may have two distinct sections, both choir and presbytery. It is often square ended or has a projecting Lady Chapel, dedicated to the Virgin Mary. In France the eastern end is often polygonal and surrounded by a walkway called an ambulatory and sometimes a ring of chapels called a "chevet". While German churches are often similar to those of France, in Italy, the eastern projection beyond the transept is usually just a shallow apsidal chapel containing the sanctuary, as at Florence Cathedral.
Is there an answer to this question: What shape does the eastern end often exhibit in France?

Answer:
polygonal