input question: Extract the answer to the question from the following context. Question: What is needed to prove the theory? Context: In the early 11th century, the Muslim physicist Ibn al-Haytham (Alhacen or Alhazen) discussed space perception and its epistemological implications in his Book of Optics (1021), he also rejected Aristotle's definition of topos (Physics IV) by way of geometric demonstrations and defined place as a mathematical spatial extension. His experimental proof of the intromission model of vision led to changes in the understanding of the visual perception of space, contrary to the previous emission theory of vision supported by Euclid and Ptolemy. In "tying the visual perception of space to prior bodily experience, Alhacen unequivocally rejected the intuitiveness of spatial perception and, therefore, the autonomy of vision. Without tangible notions of distance and size for correlation, sight can tell us next to nothing about such things."???
output answer: vision

input question: Extract the answer to the question from the following context. Question: What made Bach's Well-Tempered Clavier happen? Context: The theories surrounding equal temperament began to be put in wider practice, especially as it enabled a wider range of chromatic possibilities in hard-to-tune keyboard instruments. Although Bach did not use equal temperament, as a modern piano is generally tuned, changes in the temperaments from the meantone system, common at the time, to various temperaments that made modulation between all keys musically acceptable, made possible Bach's Well-Tempered Clavier.???
output answer: changes in the temperaments from the meantone system, common at the time, to various temperaments that made modulation between all keys musically acceptable

input question: Extract the answer to the question from the following context. Question: Which Muslim sect beginning with "Ale" were regarded even worse than Jews and Christians? Context: Muslim sects regarded as heretical, such as the Druze, Ismailis, Alevis, and Alawites, ranked below Jews and Christians. In 1514, Sultan Selim I, nicknamed "the Grim" because of his cruelty, ordered the massacre of 40,000 Anatolian Alevis (Qizilbash), whom he considered heretics, reportedly proclaiming that "the killing of one Alevi had as much otherworldly reward as killing 70 Christians."[page needed] Selim was also responsible for an unprecedented and rapid expansion of the Ottoman Empire into the Middle East, especially through his conquest of the entire Mamluk Sultanate of Egypt, which included much of the region. With these conquests, Selim further solidified the Ottoman claim for being an Islamic caliphate, although Ottoman sultans had been claiming the title of caliph since the 14th century starting with Murad I (reigned 1362 to 1389). The caliphate would remain held by Ottoman sultans for the rest of the office's duration, which ended with its abolition on 3 March 1924 by the Grand National Assembly of Turkey and the exile of the last caliph, Abdülmecid II, to France.???
output answer: Alevis

input question: Extract the answer to the question from the following context. Question: What does the C in CPI stand for? Context: According to research published in 1999 by Alan Green and the Center for Public Integrity (CPI), loopholes in the ESA are commonly exploited in the exotic pet trade. Although the legislation prohibits interstate and foreign transactions for list species, no provisions are made for in-state commerce, allowing these animals to be sold to roadside zoos and private collectors. Additionally, the ESA allows listed species to be shipped across state lines as long as they are not sold. According to Green and the CPI, this allows dealers to "donate" listed species through supposed "breeding loans" to anyone, and in return they can legally receive a reciprocal monetary "donation" from the receiving party. Furthermore, an interview with an endangered species specialist at the US Fish and Wildlife Service revealed that the agency does not have sufficient staff to perform undercover investigations, which would catch these false "donations" and other mislabeled transactions.???
output answer: