Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In 1974, the unmanned AstroFlight Sunrise plane made the first solar flight. On 29 April 1979, the Solar Riser made the first flight in a solar-powered, fully controlled, man carrying flying machine, reaching an altitude of 40 feet (12 m). In 1980, the Gossamer Penguin made the first piloted flights powered solely by photovoltaics. This was quickly followed by the Solar Challenger which crossed the English Channel in July 1981. In 1990 Eric Scott Raymond in 21 hops flew from California to North Carolina using solar power. Developments then turned back to unmanned aerial vehicles (UAV) with the Pathfinder (1997) and subsequent designs, culminating in the Helios which set the altitude record for a non-rocket-propelled aircraft at 29,524 metres (96,864 ft) in 2001. The Zephyr, developed by BAE Systems, is the latest in a line of record-breaking solar aircraft, making a 54-hour flight in 2007, and month-long flights were envisioned by 2010. As of 2015, Solar Impulse, an electric aircraft, is currently circumnavigating the globe. It is a single-seat plane powered by solar cells and capable of taking off under its own power. The designed allows the aircraft to remain airborne for 36 hours.
When did the Solar Challenger cross the English Channel?
A: July 1981

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The meaning of federalism, as a political movement, and of what constitutes a 'federalist', varies with country and historical context.[citation needed] Movements associated with the establishment or development of federations can exhibit either centralising or decentralising trends.[citation needed] For example, at the time those nations were being established, factions known as "federalists" in the United States and Australia advocated the formation of strong central government. Similarly, in European Union politics, federalists mostly seek greater EU integration. In contrast, in Spain and in post-war Germany, federal movements have sought decentralisation: the transfer of power from central authorities to local units. In Canada, where Quebec separatism has been a political force for several decades, the "federalist" impulse aims to keep Quebec inside Canada.
What types of non-movements are associated with federalism?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
For the past 25 years, the Tucson Folk Festival has taken place the first Saturday and Sunday of May in downtown Tucson's El Presidio Park. In addition to nationally known headline acts each evening, the Festival highlights over 100 local and regional musicians on five stages is one of the largest free festivals in the country. All stages are within easy walking distance. Organized by the Tucson Kitchen Musicians Association, volunteers make this festival possible. KXCI 91.3-FM, Arizona's only community radio station, is a major partner, broadcasting from the Plaza Stage throughout the weekend. In addition, there are numerous workshops, events for children, sing-alongs, and a popular singer/songwriter contest. Musicians typically play 30-minute sets, supported by professional audio staff volunteers. A variety of food and crafts are available at the festival, as well as local micro-brews. All proceeds from sales go to fund future festivals.
Who runs the Tucson Folk Festival?
A: Tucson Kitchen Musicians Association

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Arabic translation efforts and techniques are important to Western translation traditions due to centuries of close contacts and exchanges. Especially after the Renaissance, Europeans began more intensive study of Arabic and Persian translations of classical works as well as scientific and philosophical works of Arab and oriental origins. Arabic and, to a lesser degree, Persian became important sources of material and perhaps of techniques for revitalized Western traditions, which in time would overtake the Islamic and oriental traditions.
What would Western traditions eventually avoid?
A:
unanswerable