Problem: Classical music:

The major time divisions of classical music up to 1900 are the early music period, which includes Medieval (500–1400) and Renaissance (1400–1600) eras, and the Common practice period, which includes the Baroque (1600–1750), Classical (1750–1830) and Romantic (1804–1910) eras. Since 1900, classical periods have been reckoned more by calendar century than by particular stylistic movements that have become fragmented and difficult to define. The 20th century calendar period (1901–2000) includes most of the early modern musical era (1890–1930), the entire high modern (mid 20th-century), and the first 25 years of the contemporary or postmodern musical era (1975–current). The 21st century has so far been characterized by a continuation of the contemporary/postmodern musical era.

What period was from 500-1400?
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A: Medieval


Problem: London:

The London Natural History Society suggest that London is "one of the World's Greenest Cities" with more than 40 percent green space or open water. They indicate that 2000 species of flowering plant have been found growing there and that the tidal Thames supports 120 species of fish. They also state that over 60 species of bird nest in central London and that their members have recorded 47 species of butterfly, 1173 moths and more than 270 kinds of spider around London. London's wetland areas support nationally important populations of many water birds. London has 38 Sites of Special Scientific Interest (SSSIs), two National Nature Reserves and 76 Local Nature Reserves.

How many different species of plant life are known to grow in London?
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A: 2000


Problem: Mali:

From 22 March through 26 March 1991, mass pro-democracy rallies and a nationwide strike was held in both urban and rural communities, which became known as les evenements ("the events") or the March Revolution. In Bamako, in response to mass demonstrations organized by university students and later joined by trade unionists and others, soldiers opened fire indiscriminately on the nonviolent demonstrators. Riots broke out briefly following the shootings. Barricades as well as roadblocks were erected and Traoré declared a state of emergency and imposed a nightly curfew. Despite an estimated loss of 300 lives over the course of four days, nonviolent protesters continued to return to Bamako each day demanding the resignation of the dictatorial president and the implementation of democratic policies.

What was held in both urban and rural communities throughout the 1990s?
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A: unanswerable


Problem: Great Plains:

The railroads opened up the Great Plains for settlement, for now it was possible to ship wheat and other crops at low cost to the urban markets in the East, and Europe. Homestead land was free for American settlers. Railroads sold their land at cheap rates to immigrants in expectation they would generate traffic as soon as farms were established. Immigrants poured in, especially from Germany and Scandinavia. On the plains, very few single men attempted to operate a farm or ranch by themselves; they clearly understood the need for a hard-working wife, and numerous children, to handle the many chores, including child-rearing, feeding and clothing the family, managing the housework, feeding the hired hands, and, especially after the 1930s, handling paperwork and financial details. During the early years of settlement, farm women played an integral role in assuring family survival by working outdoors. After approximately one generation, women increasingly left the fields, thus redefining their roles within the family. New technology including sewing and washing machines encouraged women to turn to domestic roles. The scientific housekeeping movement, promoted across the land by the media and government extension agents, as well as county fairs which featured achievements in home cookery and canning, advice columns for women regarding farm bookkeeping, and home economics courses in the schools.

what mainly opened the great plains for settlement?
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A:
railroads