[Q]: A friend asked me to answer this question: What ruler was overthrown by a group whose factional conflicts caused the Second Bulgarian Empire to disintegrate?, using the article: After the conquest of Bulgaria, Basil II prevented revolts by retaining the rule of local nobility and relieving their lands of the obligation to pay taxes in gold, allowing tax in kind instead. The Bulgarian Patriarchate was reduced to an archbishopric, but retained its autocephalous status and its dioceses. Byzantine domestic policies changed after Basil's death and a series of unsuccessful rebellions broke out, the largest being led by Peter Delyan. In 1185 Asen dynasty nobles Ivan Asen I and Peter IV organized a major uprising which resulted in the re-establishment of the Bulgarian state. Ivan Asen and Peter laid the foundations of the Second Bulgarian Empire with Tarnovo as the capital. Kaloyan, the third of the Asen monarchs, extended his dominion to Belgrade and Ohrid. He acknowledged the spiritual supremacy of the pope and received a royal crown from a papal legate. The empire reached its zenith under Ivan Asen II (1218–1241), when its borders expanded as far as the coast of Albania, Serbia and Epirus, while commerce and culture flourished. Ivan Asen's rule was also marked by a shift away from Rome in religious matters.The Asen dynasty became extinct in 1257. Internal conflicts and incessant Byzantine and Hungarian attacks followed, enabling the Mongols to establish suzerainty over the weakened Bulgarian state. In 1277, swineherd Ivaylo led a great peasant revolt that chased the Mongols out of Bulgaria and briefly made him emperor. He was overthrown in 1280 by the feudal landlords, whose factional conflicts caused the Second Bulgarian Empire to disintegrate into small feudal dominions by the 14th century. These fragmented rump states—two tsardoms at Vidin and Tarnovo and the Despotate of Dobrudzha—became easy prey for a new threat arriving from the Southeast: the Ottoman Turks., what would be the answer ?
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[A]: Ivaylo

input: Please answer the following: A friend asked me to answer this question: What quality of Paraceratherium's probably meant it didn't have many animals trying to eat it?, using the article: Paraceratherium is an extinct genus of hornless rhinoceros, and one of the largest terrestrial mammals that has ever existed. It lived from the early to late Oligocene epoch (34–23 million years ago); its remains have been found across Eurasia between China and the Balkans. It is classified as a member of the hyracodont subfamily Indricotheriinae. Paraceratherium means "near the hornless beast", in reference to Aceratherium, the genus in which the type species P. bugtiense was originally placed. The exact size of Paraceratherium is unknown because of the incompleteness of the fossils. Its weight is estimated to have been 15 to 20 tonnes (33,000 to 44,000 lb) at most; the shoulder height was about 4.8 metres (15.7 feet), and the length about 7.4 metres (24.3 feet). The legs were long and pillar-like. The long neck supported a skull that was about 1.3 metres (4.3 ft) long. It had large, tusk-like incisors and a nasal incision that suggests it had a prehensile upper lip or proboscis (trunk). The lifestyle of Paraceratherium may have been similar to that of modern large mammals such as the elephants and extant rhinoceroses. Because of its size, it would have had few predators and a slow rate of reproduction. It was a browser, eating mainly leaves, soft plants, and shrubs. It lived in habitats ranging from arid deserts with a few scattered trees to subtropical forests. The reasons for the animal's extinction are unknown, but various factors have been proposed., what would be the answer ?
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output: its size

Problem: A friend asked me to answer this question: What is the last name of the band member who was upset when a past band member visited the studio and no one initially recognized him?, using the article: After a tour of the UK performing Dark Side, Pink Floyd returned to the studio in January 1975 and began work on their ninth studio album, Wish You Were Here. Parsons declined an offer to continue working with them, becoming successful in his own right with the Alan Parsons Project, and so the band turned to Brian Humphries. Initially, they found it difficult to compose new material; the success of The Dark Side of the Moon had left Pink Floyd physically and emotionally drained. Wright later described these early sessions as "falling within a difficult period" and Waters found them "tortuous". Gilmour was more interested in improving the band's existing material. Mason's failing marriage left him in a general malaise and with a sense of apathy, both of which interfered with his drumming.Despite the lack of creative direction, Waters began to visualise a new concept after several weeks. During 1974, Pink Floyd had sketched out three original compositions and had performed them at a series of concerts in Europe. These compositions became the starting point for a new album whose opening four-note guitar phrase, composed purely by chance by Gilmour, reminded Waters of Barrett. The songs provided a fitting summary of the rise and fall of their former bandmate. Waters commented: "Because I wanted to get as close as possible to what I felt ... [that] indefinable, inevitable melancholy about the disappearance of Syd."While Pink Floyd were working on the album, Barrett made an impromptu visit to the studio. Thorgerson recalled that he "sat round and talked for a bit, but he wasn't really there". He had changed significantly in appearance, so much so that the band did not initially recognise him. Waters was reportedly deeply upset by the experience. Most of Wish You Were Here premiered on 5 July 1975, at an open-air music festival at Knebworth. Released in September, it reached number one in both the UK and the US., what would be the answer ?

A:
Waters