Problem: Energy:

For example, consider electronpositron annihilation, in which the rest mass of individual particles is destroyed, but the inertia equivalent of the system of the two particles (its invariant mass) remains (since all energy is associated with mass), and this inertia and invariant mass is carried off by photons which individually are massless, but as a system retain their mass. This is a reversible process the inverse process is called pair creation in which the rest mass of particles is created from energy of two (or more) annihilating photons. In this system the matter (electrons and positrons) is destroyed and changed to non-matter energy (the photons). However, the total system mass and energy do not change during this interaction.

what is created and changed to non-matter energy?
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A: unanswerable

Problem: In four months, Aonuma's team managed to present realistic horseback riding,[l] which Nintendo later revealed to the public with a trailer at Electronic Entertainment Expo 2004. The game was scheduled to be released the next year, and was no longer a follow-up to The Wind Waker; a true sequel to it was released for the Nintendo DS in 2007, in the form of Phantom Hourglass. Miyamoto explained in interviews that the graphical style was chosen to satisfy demand, and that it better fit the theme of an older incarnation of Link. The game runs on a modified The Wind Waker engine.
Where did Nintendo preview the horseback riding feature?
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Answer: Electronic Entertainment Expo 2004

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The majority of Sicilians preferred independence to the Savoia kingdom; in 1866, Palermo became the seat of a week-long popular rebellion, which was finally crushed after Martial law was declared. The Italian government blamed anarchists and the Church, specifically the Archbishop of Palermo, for the rebellion and began enacting anti-Sicilian and anti-clerical policies. A new cultural, economic and industrial growth was spurred by several families, like the Florio, the Ducrot, the Rutelli, the Sandron, the Whitaker, the Utveggio, and others. In the early twentieth century Palermo expanded outside the old city walls, mostly to the north along the new boulevards Via Roma, Via Dante, Via Notarbartolo, and Viale della Liberta. These roads would soon boast a huge number of villas in the Art Nouveau style. Many of these were designed by the famous architect Ernesto Basile. The Grand Hotel Villa Igiea, designed by Ernesto Basile for the Florio family, is a good example of Palermitan Art Nouveau. The huge Teatro Massimo was designed in the same period by Giovan Battista Filippo Basile, and built by the Rutelli & Machi building firm of the industrial and old Rutelli Italian family in Palermo, and was opened in 1897.
In what style were the villas in the new expanded Palermo?
A: Art Nouveau

Context and question: The name iPod was proposed by Vinnie Chieco, a freelance copywriter, who (with others) was called by Apple to figure out how to introduce the new player to the public. After Chieco saw a prototype, he thought of the movie 2001: A Space Odyssey and the phrase "Open the pod bay door, Hal!", which refers to the white EVA Pods of the Discovery One spaceship. Chieco saw an analogy to the relationship between the spaceship and the smaller independent pods in the relationship between a personal computer and the music player. Apple researched the trademark and found that it was already in use. Joseph N. Grasso of New Jersey had originally listed an "iPod" trademark with the U.S. Patent and Trademark Office (USPTO) in July 2000 for Internet kiosks. The first iPod kiosks had been demonstrated to the public in New Jersey in March 1998, and commercial use began in January 2000, but had apparently been discontinued by 2001. The trademark was registered by the USPTO in November 2003, and Grasso assigned it to Apple Computer, Inc. in 2005.
Who held the original trademark for the iPod name?
Answer: Joseph N. Grasso

Question: The first overseas deployment of Canadian military forces occurred during the Second Boer War, when several units were raised to serve under British command. Similarly, when the United Kingdom entered into conflict with Germany in the First World War, Canadian troops were called to participate in European theatres. The Canadian Crown-in-Council then decided to send its forces into the Second World War, as well as the Korean War.
Is there an answer to this question: What wars did the Canadian Council-in-Crown send its forces into?

Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
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]
What substance helped demonstrate the first blue electroluminescence?
A:
zinc-doped gallium nitride