Problem: Electric motor:

The first commutator DC electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832. Following Sturgeon's work, a commutator-type direct-current electric motor made with the intention of commercial use was built by the American inventor Thomas Davenport, which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press. Due to the high cost of primary battery power, the motors were commercially unsuccessful and Davenport went bankrupt. Several inventors followed Sturgeon in the development of DC motors but all encountered the same battery power cost issues. No electricity distribution had been developed at the time. Like Sturgeon's motor, there was no practical commercial market for these motors.

How slow did Sturgeon and Davenport's motors run?
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A: unanswerable

Problem: Miami:

Miami is partitioned into many different sections, roughly into North, South, West and Downtown. The heart of the city is Downtown Miami and is technically on the eastern side of the city. This area includes Brickell, Virginia Key, Watson Island, and PortMiami. Downtown is South Florida's central business district, and Florida's largest and most influential central business district. Downtown has the largest concentration of international banks in the U.S. along Brickell Avenue. Downtown is home to many major banks, courthouses, financial headquarters, cultural and tourist attractions, schools, parks and a large residential population. East of Downtown, across Biscayne Bay is South Beach. Just northwest of Downtown, is the Civic Center, which is Miami's center for hospitals, research institutes and biotechnology with hospitals such as Jackson Memorial Hospital, Miami VA Hospital, and the University of Miami's Leonard M. Miller School of Medicine.

On what street is the lowest concentration of international banks in the US?
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A: unanswerable

Problem: Child labour:

On 23 June 1757, the English East India Company defeated Siraj-ud-Daula, the Nawab of Bengal, in the Battle of Plassey. The British thus became masters of east India (Bengal, Bihar, Orissa) a prosperous region with a flourishing agriculture, industry and trade. This led to a large amount of children being forced into labour due to the increasing need of cheap labour to produce large numbers of goods. Many multinationals often employed children because that they can be recruited for less pay, and have more endurance to utilise in factory environments. Another reason many Indian children were hired was because they lack knowledge of their basic rights, they did not cause trouble or complain, and they were often more trustworthy. The innocence that comes with childhood was utilised to make a profit by many and was encouraged by the need for family income.

How did India child workers act?
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A: they did not cause trouble or complain

Problem: Mandolin:

The second decline was not as complete as the first. Thousands of people had learned to play the instrument. Even as the second wave of mandolin popularity declined in the early 20th century, new versions of the mandolin began to be used in new forms of music. Luthiers created the resonator mandolin, the flatback mandolin, the carved-top or arched-top mandolin, the mandolin-banjo and the electric mandolin. Musicians began playing it in Celtic, Bluegrass, Jazz and Rock-n-Roll styles and Classical too.

When did the first wave of mandolin popularity decline?
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A:
unanswerable