Problem: Copper:

Copper is biostatic, meaning bacteria will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.

What has fake copper been replaced with in the building of ships?
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A: unanswerable

Problem: Data compression:

If the data to be compressed is analog (such as a voltage that varies with time), quantization is employed to digitize it into numbers (normally integers). This is referred to as analog-to-digital (A/D) conversion. If the integers generated by quantization are 8 bits each, then the entire range of the analog signal is divided into 256 intervals and all the signal values within an interval are quantized to the same number. If 16-bit integers are generated, then the range of the analog signal is divided into 65,536 intervals.

What is a voltage that is divided with time classified as?
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A: unanswerable

Problem: Tajikistan:

The Kushan Empire, a collection of Yuezhi tribes, took control of the region in the first century CE and ruled until the 4th century CE during which time Buddhism, Nestorian Christianity, Zoroastrianism, and Manichaeism were all practiced in the region. Later the Hephthalite Empire, a collection of nomadic tribes, moved into the region and Arabs brought Islam in the early eighth century. Central Asia continued in its role as a commercial crossroads, linking China, the steppes to the north, and the Islamic heartland.

Central Africa continued its role as what?
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A: unanswerable

Problem: New York City:

New York's non-white population was 36,620 in 1890. New York City was a prime destination in the early twentieth century for African Americans during the Great Migration from the American South, and by 1916, New York City was home to the largest urban African diaspora in North America. The Harlem Renaissance of literary and cultural life flourished during the era of Prohibition. The larger economic boom generated construction of skyscrapers competing in height and creating an identifiable skyline.

What was the name of the Prohibition-era African-American cultural flourishing in New York?
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A:
Harlem Renaissance