Problem: Umayyad Caliphate:

Around 746, Abu Muslim assumed leadership of the Hashimiyya in Khurasan. In 747, he successfully initiated an open revolt against Umayyad rule, which was carried out under the sign of the black flag. He soon established control of Khurasan, expelling its Umayyad governor, Nasr ibn Sayyar, and dispatched an army westwards. Kufa fell to the Hashimiyya in 749, the last Umayyad stronghold in Iraq, Wasit, was placed under siege, and in November of the same year Abu al-Abbas was recognized as the new caliph in the mosque at Kufa.[citation needed] At this point Marwan mobilized his troops from Harran and advanced toward Iraq. In January 750 the two forces met in the Battle of the Zab, and the Umayyads were defeated. Damascus fell to the Abbasids in April, and in August, Marwan was killed in Egypt.

Who was the Umayyad governor of Khurasan who was defeated by Abu Muslim?
---
A: Nasr ibn Sayyar

Problem: Since LED efficacy is inversely proportional to operating temperature, LED technology is well suited for supermarket freezer lighting. Because LEDs produce less waste heat than incandescent lamps, their use in freezers can save on refrigeration costs as well. However, they may be more susceptible to frost and snow buildup than incandescent lamps, so some LED lighting systems have been designed with an added heating circuit. Additionally, research has developed heat sink technologies that will transfer heat produced within the junction to appropriate areas of the light fixture.
LED efficacy is not inversely proportional to what?
---
Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
From 1820 to 1848 Sicily was shaken by upheavals, which culminated on 12 January 1848, with a popular insurrection, the first one in Europe that year, led by Giuseppe La Masa. A parliament and constitution were proclaimed. The first president was Ruggero Settimo. The Bourbons reconquered Palermo in 1849, and remained under their rule until the time of Giuseppe Garibaldi. The famous general entered Palermo with his troops (the "Thousands") on 27 May 1860. After the plebiscite later that year Palermo, along with the rest of Sicily, became part of the new Kingdom of Italy (1861).
Who reconqured Palermo in the 18th century?
A: unanswerable

Context and question: Standing at 117 metres (384 feet) in height and 360 metres (1,180 feet) in width, the Potala Palace is the most important example of Tibetan architecture. Formerly the residence of the Dalai Lama, it contains over one thousand rooms within thirteen stories, and houses portraits of the past Dalai Lamas and statues of the Buddha. It is divided between the outer White Palace, which serves as the administrative quarters, and the inner Red Quarters, which houses the assembly hall of the Lamas, chapels, 10,000 shrines, and a vast library of Buddhist scriptures. The Potala Palace is a World Heritage Site, as is Norbulingka, the former summer residence of the Dalai Lama.
What is Norbulingka?
Answer: former summer residence of the Dalai Lama

Question: Following the successes of his trial-run games, Foster moved ahead with his idea for arena football. He founded the Arena Football League with four teams: the Pittsburgh Gladiators, Denver Dynamite, Washington Commandos, and Chicago Bruisers. Foster appointed legendary Darrel "Mouse" Davis, godfather of the "run and shoot" and modern pro offenses, as executive director of football operations. Davis hired the original coaches and was the architect of the league's original wide-open offensive playbooks.
Is there an answer to this question: Along with the Chicago Bruisers, Denver Dynamite and Pittsburgh Gladiators, what team was one of the original AFL teams?

Answer: Washington Commandos

Question: The rivalries between the Arab tribes had caused unrest in the provinces outside Syria, most notably in the Second Muslim Civil War of 680692 CE and the Berber Revolt of 740743 CE. During the Second Civil War, leadership of the Umayyad clan shifted from the Sufyanid branch of the family to the Marwanid branch. As the constant campaigning exhausted the resources and manpower of the state, the Umayyads, weakened by the Third Muslim Civil War of 744747 CE, were finally toppled by the Abbasid Revolution in 750 CE/132 AH. A branch of the family fled across North Africa to Al-Andalus, where they established the Caliphate of Cordoba, which lasted until 1031 before falling due to the Fitna of al-Andalus.
Is there an answer to this question: What war strengthened the Umayyads?

Answer:
unanswerable