Problem: Thuringia:

Environmental damage in Thuringia has been reduced to a large extent after 1990. The condition of forests, rivers and air was improved by modernizing factories, houses (decline of coal heating) and cars, and contaminated areas such as the former Uranium surface mines around Ronneburg have been remediated. Today's environmental problems are the salination of the Werra river, caused by discharges of K+S salt mines around Unterbreizbach and overfertilisation in agriculture, damaging the soil and small rivers.

What has been done to former Uranium surface mines around Ronneburg?
---
A: Uranium surface mines around Ronneburg have been remediated

Problem: Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. PV converts light into electric current using the photoelectric effect.
How is sunlight converted into electricity?
---
Answer: either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP)

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Since the system's launch, production costs have been reduced significantly as a result of phasing out the Emotion Engine chip and falling hardware costs. The cost of manufacturing Cell microprocessors has fallen dramatically as a result of moving to the 65 nm production process, and Blu-ray Disc diodes have become cheaper to manufacture. As of January 2008, each unit cost around $400 to manufacture; by August 2009, Sony had reduced costs by a total of 70%, meaning it only costs Sony around $240 per unit.
What's the name of the microprocessor produced by the 56 nm process?
A: unanswerable

Context and question: One of the founding members, East Germany was allowed to re-arm by the Soviet Union and the National People's Army was established as the armed forces of the country to counter the rearmament of West Germany.
Which nation was permitted rearmament by the foundation of the Warsaw Pact?
Answer: East Germany

Question: Eton College has links with some private schools in India today, maintained from the days of the British Raj, such as The Doon School and Mayo College. Eton College is also a member of the G20 Schools Group, a collection of college preparatory boarding schools from around the world, including Turkey's Robert College, the United States' Phillips Academy and Phillips Exeter Academy, Australia's Scotch College, Melbourne Grammar School and Launceston Church Grammar School, Singapore's Raffles Institution, and Switzerland's International School of Geneva. Eton has recently fostered[when?] a relationship with the Roxbury Latin School, a traditional all-boys private school in Boston, USA. Former Eton headmaster and provost Sir Eric Anderson shares a close friendship with Roxbury Latin Headmaster emeritus F. Washington Jarvis; Anderson has visited Roxbury Latin on numerous occasions, while Jarvis briefly taught theology at Eton after retiring from his headmaster post at Roxbury Latin. The headmasters' close friendship spawned the Hennessy Scholarship, an annual prize established in 2005 and awarded to a graduating RL senior for a year of study at Eton. Hennessy Scholars generally reside in Wotton house.
Is there an answer to this question: What is the G20 School's Group?

Answer: a collection of college preparatory boarding schools from around the world

Brasilia is known as a departing point for the practice of unpowered air sports, sports that may be practiced with hang gliding or paragliding wings. Practitioners of such sports reveal that, because of the city's dry weather, the city offers strong thermal winds and great "cloud-streets", which is also the name for a manoeuvre quite appreciated by practitioners. In 2003, Brasilia hosted the 14th Hang Gliding World Championship, one of the categories of free flying. In August 2005, the city hosted the 2nd stage of the Brazilian Hang Gliding Championship.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What air sports event did Brasilia host in 2003?
Ah, so..
the 14th Hang Gliding World Championship