Problem: Incandescent light bulb:

An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to a high temperature, by passing an electric current through it, until it glows with visible light (incandescence). The hot filament is protected from oxidation with a glass or quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is prevented by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electric current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

Which part of the incandescent light bulb is heated?
---
A: wire filament

Problem: Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing investment opportunities without the need for specific economic support," and added that "cost reductions in critical technologies, such as wind and solar, are set to continue." As of 2011[update], there have been substantial reductions in the cost of solar and wind technologies:
As of what year when have there not been substantial reductions in the cost of solar and wind technologies?
---
Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The most prominent struggle for power was the conflict that erupted after the death of Yaroslav the Wise. The rivaling Principality of Polotsk was contesting the power of the Grand Prince by occupying Novgorod, while Rostislav Vladimirovich was fighting for the Black Sea port of Tmutarakan belonging to Chernihiv.[citation needed] Three of Yaroslav's sons that first allied together found themselves fighting each other especially after their defeat to the Cuman forces in 1068 at the Battle of the Alta River. At the same time an uprising took place in Kiev, bringing to power Vseslav of Polotsk who supported the traditional Slavic paganism.[citation needed] The ruling Grand Prince Iziaslav fled to Poland asking for support and in couple of years returned to establish the order.[citation needed] The affairs became even more complicated by the end of the 11th century driving the state into chaos and constant warfare. On the initiative of Vladimir II Monomakh in 1097 the first federal council of Kievan Rus took place near Chernihiv]in the city of Liubech with the main intention to find an understanding among the fighting sides. However even though that did not really stop the fighting, it certainly cooled things off.[citation needed]
Where did the first federal council of Rus take place in 1097?
A: city of Liubech

Context and question: Because the spring equinox was tied to the date of Easter, the Roman Catholic Church considered the seasonal drift in the date of Easter undesirable. The Church of Alexandria celebrated Easter on the Sunday after the 14th day of the moon (computed using the Metonic cycle) that falls on or after the vernal equinox, which they placed on 21 March. However, the Church of Rome still regarded 25 March as the equinox (until 342) and used a different cycle to compute the day of the moon. In the Alexandrian system, since the 14th day of the Easter moon could fall at earliest on 21 March its first day could fall no earlier than 8 March and no later than 5 April. This meant that Easter varied between 22 March and 25 April. In Rome, Easter was not allowed to fall later than 21 April, that being the day of the Parilia or birthday of Rome and a pagan festival.The first day of the Easter moon could fall no earlier than 5 March and no later than 2 April.
What did the church of Rome use the metonic cycle to determine?
Answer: unanswerable

Question: To pay for his military campaigns and colonial expansion, Emperor Wu nationalized several private industries. He created central government monopolies administered largely by former merchants. These monopolies included salt, iron, and liquor production, as well as bronze-coin currency. The liquor monopoly lasted only from 98 to 81 BC, and the salt and iron monopolies were eventually abolished in early Eastern Han. The issuing of coinage remained a central government monopoly throughout the rest of the Han dynasty. The government monopolies were eventually repealed when a political faction known as the Reformists gained greater influence in the court. The Reformists opposed the Modernist faction that had dominated court politics in Emperor Wu's reign and during the subsequent regency of Huo Guang (d. 68 BC). The Modernists argued for an aggressive and expansionary foreign policy supported by revenues from heavy government intervention in the private economy. The Reformists, however, overturned these policies, favoring a cautious, non-expansionary approach to foreign policy, frugal budget reform, and lower tax-rates imposed on private entrepreneurs.
Is there an answer to this question: In what year did Huo Guang die?

Answer: 68 BC

Question: A distinct Greek political identity re-emerged in the 11th century in educated circles and became more forceful after the fall of Constantinople to the Crusaders of the Fourth Crusade in 1204, so that when the empire was revived in 1261, it became in many ways a Greek national state. That new notion of nationhood engendered a deep interest in the classical past culminating in the ideas of the Neoplatonist philosopher Gemistus Pletho, who abandoned Christianity. However, it was the combination of Orthodox Christianity with a specifically Greek identity that shaped the Greeks' notion of themselves in the empire's twilight years. The interest in the Classical Greek heritage was complemented by a renewed emphasis on Greek Orthodox identity, which was reinforced in the late Medieval and Ottoman Greeks' links with their fellow Orthodox Christians in the Russian Empire. These were further strengthened following the fall of the Empire of Trebizond in 1461, after which and until the second Russo-Turkish War of 1828-29 hundreds of thousands of Pontic Greeks fled or migrated from the Pontic Alps and Armenian Highlands to southern Russia and the Russian South Caucasus (see also Greeks in Russia, Greeks in Armenia, Greeks in Georgia, and Caucasian Greeks).
Is there an answer to this question: When did the nation not reestablish itself?

Answer:
unanswerable