Input: Read this: In the early 1970s the Rolling Stones developed their hard rock sound with Exile on Main St. (1972). Initially receiving mixed reviews, according to critic Steve Erlewine it is now "generally regarded as the Rolling Stones' finest album". They continued to pursue the riff-heavy sound on albums including It's Only Rock 'n' Roll (1974) and Black and Blue (1976). Led Zeppelin began to mix elements of world and folk music into their hard rock from Led Zeppelin III (1970) and Led Zeppelin IV (1971). The latter included the track "Stairway to Heaven", which would become the most played song in the history of album-oriented radio. Deep Purple continued to define hard rock, particularly with their album Machine Head (1972), which included the tracks "Highway Star" and "Smoke on the Water". In 1975 guitarist Ritchie Blackmore left, going on to form Rainbow and after the break-up of the band the next year, vocalist David Coverdale formed Whitesnake. 1970 saw The Who release Live at Leeds, often seen as the archetypal hard rock live album, and the following year they released their highly acclaimed album Who's Next, which mixed heavy rock with extensive use of synthesizers. Subsequent albums, including Quadrophenia (1973), built on this sound before Who Are You (1978), their last album before the death of pioneering rock drummer Keith Moon later that year.
Question: Who said of the album Exile on Main St.; it was not the Rolling Stones finest album?

Output: unanswerable

QUES: Chopin's mazurkas and waltzes are all in straightforward ternary or episodic form, sometimes with a coda. The mazurkas often show more folk features than many of his other works, sometimes including modal scales and harmonies and the use of drone basses. However, some also show unusual sophistication, for example Op. 63 No. 3, which includes a canon at one beat's distance, a great rarity in music.

What does Chopin's Op. 63 No. 3 have that is rare?
What is the answer?
ANS: a canon at one beat's distance

QUES: Between 7 September 1940 and 21 May 1941, 16 British cities suffered aerial raids with at least 100 long tons of high explosives. Over a period of 267 days, London was attacked 71 times, Birmingham, Liverpool and Plymouth eight times, Bristol six, Glasgow five, Southampton four, Portsmouth and Hull three and a minimum of one large raid on eight other cities. This was a result of a rapid escalation starting on 24 August 1940, when night bombers aiming for RAF airfields drifted off course and accidentally destroyed several London homes, killing civilians, combined with the UK Prime Minister Winston Churchill's retaliatory bombing of Berlin on the following night.[clarification needed]
How many days did the aerial raids on Great Britain last?

ANS: 267 days

In the early 20th century Valencia was an industrialised city. The silk industry had disappeared, but there was a large production of hides and skins, wood, metals and foodstuffs, this last with substantial exports, particularly of wine and citrus. Small businesses predominated, but with the rapid mechanisation of industry larger companies were being formed. The best expression of this dynamic was in the regional exhibitions, including that of 1909 held next to the pedestrian avenue L'Albereda (Paseo de la Alameda), which depicted the progress of agriculture and industry. Among the most architecturally successful buildings of the era were those designed in the Art Nouveau style, such as the North Station (Gare du Nord) and the Central and Columbus markets.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What markets were built in the Art Nouveau style?
Ah, so.. Central and Columbus

Question: The Acta Constitutiva de la Federacion of January 31, 1824, and the Federal Constitution of October 4, 1824, fixed the political and administrative organization of the United Mexican States after the Mexican War of Independence. In addition, Section XXVIII of Article 50 gave the new Congress the right to choose where the federal government would be located. This location would then be appropriated as federal land, with the federal government acting as the local authority. The two main candidates to become the capital were Mexico City and Queretaro.
Try to answer this question if possible: What type of land is Mexico City?
Answer: federal

QUES: Since 1066, when Harold Godwinson and William the Conqueror were crowned, the coronations of English and British monarchs have been held there. There have been at least 16 royal weddings at the abbey since 1100. Two were of reigning monarchs (Henry I and Richard II), although, before 1919, there had been none for some 500 years.
How many royal weddings have occurred at the abbey?

ANS:
16