Problem: Tucson, Arizona:

Tucson (/tusn/ /tusn/) is a city and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census put the population at 520,116, while the 2013 estimated population of the entire Tucson metropolitan statistical area (MSA) was 996,544. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA), with a total population of 980,263 as of the 2010 Census. Tucson is the second-largest populated city in Arizona behind Phoenix, both of which anchor the Arizona Sun Corridor. The city is located 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.-Mexico border. Tucson is the 33rd largest city and the 59th largest metropolitan area in the United States. Roughly 150 Tucson companies are involved in the design and manufacture of optics and optoelectronics systems, earning Tucson the nickname Optics Valley.

What is the largest populated city in Arizona?
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A: Phoenix

Problem: Classical music:

Given the wide range of styles in classical music, from Medieval plainchant sung by monks to Classical and Romantic symphonies for orchestra from the 1700s and 1800s to avant-garde atonal compositions for solo piano from the 1900s, it is difficult to list characteristics that can be attributed to all works of that type. However, there are characteristics that classical music contains that few or no other genres of music contain, such as the use of a printed score and the performance of very complex instrumental works (e.g., the fugue). As well, although the symphony did not exist through the entire classical music period, from the mid-1700s to the 2000s the symphony ensembleand the works written for ithave become a defining feature of classical music.

The use of a printed score and the performance of very complex instrumental works are characteristics of what?
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A: classical music

Problem: Umayyad Caliphate:

Mu'awiyah introduced postal service, Abd al-Malik extended it throughout his empire, and Walid made full use of it. The Umayyad Caliph Abd al-Malik developed a regular postal service. Umar bin Abdul-Aziz developed it further by building caravanserais at stages along the Khurasan highway. Relays of horses were used for the conveyance of dispatches between the caliph and his agents and officials posted in the provinces. The main highways were divided into stages of 12 miles (19 km) each and each stage had horses, donkeys or camels ready to carry the post. Primarily the service met the needs of Government officials, but travellers and their important dispatches were also benefitted by the system. The postal carriages were also used for the swift transport of troops. They were able to carry fifty to a hundred men at a time. Under Governor Yusuf bin Umar, the postal department of Iraq cost 4,000,000 dirhams a year.

In kilometers, how far apart was each stage of the Umayyad highways?
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A: 19

Problem: Child labour:

The cocoa industry was accused of profiting from child slavery and trafficking. The European Cocoa Association dismissed these accusations as "false and excessive" and the industry said the reports were not representative of all areas. Later the industry acknowledged the working conditions for children were unsatisfactory and children's rights were sometimes violated and acknowledged the claims could not be ignored. In a BBC interview, the ambassador for Ivory Coast to the United Kingdom called these reports of widespread use of slave child labour by 700,000 cocoa farmers as absurd and inaccurate.

Who claimed these reports as being inaccurate?
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A:
ambassador for Ivory Coast to the United Kingdom