Input: Read this: The first British patent for the use of asphalt/bitumen was 'Cassell's patent asphalte or bitumen' in 1834. Then on 25 November 1837, Richard Tappin Claridge patented the use of Seyssel asphalt (patent #7849), for use in asphalte pavement, having seen it employed in France and Belgium when visiting with Frederick Walter Simms, who worked with him on the introduction of asphalt to Britain. Dr T. Lamb Phipson writes that his father, Samuel Ryland Phipson, a friend of Claridge, was also "instrumental in introducing the asphalte pavement (in 1836)". Indeed, mastic pavements had been previously employed at Vauxhall by a competitor of Claridge, but without success.
Question: In what year was Cassell's patent France or Belgium issued?

Output: unanswerable


Input: Read this: Around 746, Abu Muslim assumed leadership of the Hashimiyya in Khurasan. In 747, he successfully initiated an open revolt against Umayyad rule, which was carried out under the sign of the black flag. He soon established control of Khurasan, expelling its Umayyad governor, Nasr ibn Sayyar, and dispatched an army westwards. Kufa fell to the Hashimiyya in 749, the last Umayyad stronghold in Iraq, Wasit, was placed under siege, and in November of the same year Abu al-Abbas was recognized as the new caliph in the mosque at Kufa.[citation needed] At this point Marwan mobilized his troops from Harran and advanced toward Iraq. In January 750 the two forces met in the Battle of the Zab, and the Umayyads were defeated. Damascus fell to the Abbasids in April, and in August, Marwan was killed in Egypt.
Question: Who carried out a revolt under the sign of the white flag?

Output: unanswerable


Input: Read this: One of the central problems in the anthropology of art concerns the universality of 'art' as a cultural phenomenon. Several anthropologists have noted that the Western categories of 'painting', 'sculpture', or 'literature', conceived as independent artistic activities, do not exist, or exist in a significantly different form, in most non-Western contexts. To surmount this difficulty, anthropologists of art have focused on formal features in objects which, without exclusively being 'artistic', have certain evident 'aesthetic' qualities. Boas' Primitive Art, Claude Lévi-Strauss' The Way of the Masks (1982) or Geertz's 'Art as Cultural System' (1983) are some examples in this trend to transform the anthropology of 'art' into an anthropology of culturally specific 'aesthetics'.
Question: What categories of art do not exixt in most Wester contests?

Output: unanswerable


Input: Read this: Due to the expansion of trade and its geographical proximity, Kiev became the most important trade centre and chief among the communes; therefore the leader of Kiev gained political "control" over the surrounding areas. This princedom emerged from a coalition of traditional patriarchic family communes banded together in an effort to increase the applicable workforce and expand the productivity of the land. This union developed the first major cities in the Rus' and was the first notable form of self-government. As these communes became larger, the emphasis was taken off the family holdings and placed on the territory that surrounded. This shift in ideology became known as the verv'.
Question: What caused the decline of Kiev political power?

Output:
unanswerable