Problem: Endangered Species Act:

Green and the CPI further noted another exploit of the ESA in their discussion of the critically endangered cotton-top tamarin (Saguinus oedipus). Not only had they found documentation that 151 of these primates had inadvertently made their way from the Harvard-affiliated New England Regional Primate Research Center into the exotic pet trade through the aforementioned loophole, but in October 1976, over 800 cotton-top tamarins were imported into the United States in order to beat the official listing of the species under the ESA.

What happened in 1976 that impacted this primate's classification as Endanger?
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A: over 800 cotton-top tamarins were imported into the United States


Problem: Infrared:

Infrared reflectography (fr; it; es), as called by art conservators, can be applied to paintings to reveal underlying layers in a completely non-destructive manner, in particular the underdrawing or outline drawn by the artist as a guide. This often reveals the artist's use of carbon black, which shows up well in reflectograms, as long as it has not also been used in the ground underlying the whole painting. Art conservators are looking to see whether the visible layers of paint differ from the underdrawing or layers in between – such alterations are called pentimenti when made by the original artist. This is very useful information in deciding whether a painting is the prime version by the original artist or a copy, and whether it has been altered by over-enthusiastic restoration work. In general, the more pentimenti the more likely a painting is to be the prime version. It also gives useful insights into working practices.

What shows up particularly well in reflectograms?
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A: carbon black


Problem: Nanjing:

As in most of eastern China the ethnic makeup of Nanjing is predominantly Han nationality (98.56 percent), with 50 other minority nationalities. In 1999, 77,394 residents belonged to minority nationalities, among which the vast majority (64,832) were Hui nationalities, contributing 83.76 percent to the minority population. The second and third largest minority groups were Manchu (2,311) and Zhuang (533) nationalities. Most of the minority nationalities resided in Jianye District, comprising 9.13 percent of the district's population.

How many people of Manchu descent live in Nanjing?
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A: 2,311


Problem: Daylight saving time:

The war's end swung the pendulum back. Farmers continued to dislike DST, and many countries repealed it after the war. Britain was an exception: it retained DST nationwide but over the years adjusted transition dates for several reasons, including special rules during the 1920s and 1930s to avoid clock shifts on Easter mornings. The US was more typical: Congress repealed DST after 1919. President Woodrow Wilson, like Willett an avid golfer, vetoed the repeal twice but his second veto was overridden. Only a few US cities retained DST locally thereafter, including New York so that its financial exchanges could maintain an hour of arbitrage trading with London, and Chicago and Cleveland to keep pace with New York. Wilson's successor Warren G. Harding opposed DST as a "deception". Reasoning that people should instead get up and go to work earlier in the summer, he ordered District of Columbia federal employees to start work at 08:00 rather than 09:00 during summer 1922. Some businesses followed suit though many others did not; the experiment was not repeated.

What U.S. city kept observing DST to stay in sync with London, leading Chicago and Cleveland to follow along?
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A:
New York