Problem: American Idol:

Beginning in the tenth season[citation needed], permanent mentors were brought in during the live shows to help guide the contestants with their song choice and performance. Jimmy Iovine was the mentor in the tenth through twelfth seasons, former judge Randy Jackson was the mentor for the thirteenth season and Scott Borchetta was the mentor for the fourteenth and fifteenth season. The mentors regularly bring in guest mentors to aid them, including Akon, Alicia Keys, Lady Gaga, and current judge Harry Connick, Jr..

Who was a mentor to the contestants on American Idol in its thirteenth season? 
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A: Randy Jackson


Problem: 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.
Who never had any disagreements?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In the last two decades, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications towards becoming a mainstream electricity source. A solar cell is a device that converts light directly into electricity using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s. In 1931 a German engineer, Dr Bruno Lange, developed a photo cell using silver selenide in place of copper oxide. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the crystalline silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.5–6%. By 2012 available efficiencies exceed 20% and the maximum efficiency of research photovoltaics is over 40%.
What is a solar cell?
A: a device that converts light directly into electricity


Context and question: There are two major sports centers in Nanjing, Wutaishan Sports Center and Nanjing Olympic Sports Center. Both of these two are comprehensive sports centers, including stadium, gymnasium, natatorium, tennis court, etc. Wutaishan Sports Center was established in 1952 and it was one of the oldest and most advanced stadiums in early time of People's Republic of China.
What is special about Wutaishan Sports Center, from a historical perspective?
Answer: it was one of the oldest and most advanced stadiums in early time of People's Republic of China.


Question: Portugal has the largest aquarium in Europe, the Lisbon Oceanarium, and the Portuguese have several other notable organizations focused on science-related exhibits and divulgation, like the state agency Ciência Viva, a programme of the Portuguese Ministry of Science and Technology to the promotion of a scientific and technological culture among the Portuguese population, the Science Museum of the University of Coimbra, the National Museum of Natural History at the University of Lisbon, and the Visionarium.
Is there an answer to this question: What is the name of the largest European aquarium?

Answer: Lisbon Oceanarium


Problem: New Delhi:

Delhi Metro is being built and operated by the Delhi Metro Rail Corporation Limited (DMRC), a state-owned company with equal equity participation from Government of India and Government of National Capital Territory of Delhi. However, the organisation is under administrative control of Ministry of Urban Development, Government of India. Besides construction and operation of Delhi metro, DMRC is also involved in the planning and implementation of metro rail, monorail and high-speed rail projects in India and providing consultancy services to other metro projects in the country as well as abroad. The Delhi Metro project was spearheaded by Padma Vibhushan E. Sreedharan, the Managing Director of DMRC and popularly known as the "Metro Man" of India. He famously resigned from DMRC, taking moral responsibility for a metro bridge collapse which took five lives. Sreedharan was awarded with the prestigious Legion of Honour by the French Government for his contribution to Delhi Metro.

The Delhi Metro project was spearheaded by what Indian government figure?
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A:
Padma Vibhushan E. Sreedharan