Input: Read this: Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true.
Question: Besides big trees, what trees are more likely to have a range of different kinds of wood?

Output: mature


Input: Read this: The mandolin has been used extensively in the traditional music of England and Scotland for generations. Simon Mayor is a prominent British player who has produced six solo albums, instructional books and DVDs, as well as recordings with his mandolin quartet the Mandolinquents. The instrument has also found its way into British rock music. The mandolin was played by Mike Oldfield (and introduced by Vivian Stanshall) on Oldfield's album Tubular Bells, as well as on a number of his subsequent albums (particularly prominently on Hergest Ridge (1974) and Ommadawn (1975)). It was used extensively by the British folk-rock band Lindisfarne, who featured two members on the instrument, Ray Jackson and Simon Cowe, and whose "Fog on the Tyne" was the biggest selling UK album of 1971-1972. The instrument was also used extensively in the UK folk revival of the 1960s and 1970s with bands such as Fairport Convention and Steeleye Span taking it on as the lead instrument in many of their songs. Maggie May by Rod Stewart, which hit No. 1 on both the British charts and the Billboard Hot 100, also featured Jackson's playing. It has also been used by other British rock musicians. Led Zeppelin's bassist John Paul Jones is an accomplished mandolin player and has recorded numerous songs on mandolin including Going to California and That's the Way; the mandolin part on The Battle of Evermore is played by Jimmy Page, who composed the song. Other Led Zeppelin songs featuring mandolin are Hey Hey What Can I Do, and Black Country Woman. Pete Townshend of The Who played mandolin on the track Mike Post Theme, along with many other tracks on Endless Wire. McGuinness Flint, for whom Graham Lyle played the mandolin on their most successful single, When I'm Dead And Gone, is another example. Lyle was also briefly a member of Ronnie Lane's Slim Chance, and played mandolin on their hit How Come. One of the more prominent early mandolin players in popular music was Robin Williamson in The Incredible String Band. Ian Anderson of Jethro Tull is a highly accomplished mandolin player (beautiful track Pussy Willow), as is his guitarist Martin Barre. The popular song Please Please Please Let Me Get What I Want by The Smiths featured a mandolin solo played by Johnny Marr. More recently, the Glasgow-based band Sons and Daughters featured the mandolin, played by Ailidh Lennon, on tracks such as Fight, Start to End, and Medicine. British folk-punk icons the Levellers also regularly use the mandolin in their songs. Current bands are also beginning to use the Mandolin and its unique sound - such as South London's Indigo Moss who use it throughout their recordings and live gigs. The mandolin has also featured in the playing of Matthew Bellamy in the rock band Muse. It also forms the basis of Paul McCartney's 2007 hit "Dance Tonight." That was not the first time a Beatle played a mandolin, however; that distinction goes to George Harrison on Gone Troppo, the title cut from the 1982 album of the same name. The mandolin is taught in Lanarkshire by the Lanarkshire Guitar and Mandolin Association to over 100 people. Also more recently hard rock supergroup Them Crooked Vultures have been playing a song based primarily using a mandolin. This song was left off their debut album, and features former Led Zeppelin bassist John Paul Jones.[citation needed]
Question:  What was US's biggest selling album?

Output: unanswerable


Input: Read this: Von Neumann's team performed the world's first numerical weather forecasts on the ENIAC computer; von Neumann published the paper Numerical Integration of the Barotropic Vorticity Equation in 1950. Von Neumann's interest in weather systems and meteorological prediction led him to propose manipulating the environment by spreading colorants on the polar ice caps to enhance absorption of solar radiation (by reducing the albedo). thereby inducing global warming. Noting that the Earth was only 6 °F (3.3 °C) colder during the last glacial period, he noted that the burning of coal and oil "a general warming of the Earth by about one degree Fahrenheit."
Question: In what year did von Neumann publish the paper Numerical Integration of the Barotropic Vorticity Equation

Output: 1950


Input: Read this: The most accurate timekeeping devices are atomic clocks, which are accurate to seconds in many millions of years, and are used to calibrate other clocks and timekeeping instruments. Atomic clocks use the frequency of electronic transitions in certain atoms to measure the second. One of the most common atoms used is caesium, most modern atomic clocks probe caesium with microwaves to determine the frequency of these electron vibrations. Since 1967, the International System of Measurements bases its unit of time, the second, on the properties of caesium atoms. SI defines the second as 9,192,631,770 cycles of the radiation that corresponds to the transition between two electron spin energy levels of the ground state of the 133Cs atom.
Question: Which timekeeping devices are the least accurate?

Output:
unanswerable