Problem: Race and ethnicity in the United States Census:

In September 1997, during the process of revision of racial categories previously declared by OMB directive no. 15, the American Anthropological Association (AAA) recommended that OMB combine the "race" and "ethnicity" categories into one question to appear as "race/ethnicity" for the 2000 US Census. The Interagency Committee agreed, stating that "race" and "ethnicity" were not sufficiently defined and "that many respondents conceptualize 'race' and 'ethnicity' as one in the same  [sic] underscor[ing] the need to consolidate these terms into one category, using a term that is more meaningful to the American people."

How did racial categories appear in the US 2000 census?
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A: race/ethnicity


Problem: Armenians:

Instruments like the duduk, the dhol, the zurna and the kanun are commonly found in Armenian folk music. Artists such as Sayat Nova are famous due to their influence in the development of Armenian folk music. One of the oldest types of Armenian music is the Armenian chant which is the most common kind of religious music in Armenia. Many of these chants are ancient in origin, extending to pre-Christian times, while others are relatively modern, including several composed by Saint Mesrop Mashtots, the inventor of the Armenian alphabet. Whilst under Soviet rule, Armenian classical music composer Aram Khatchaturian became internationally well known for his music, for various ballets and the Sabre Dance from his composition for the ballet Gayane.

What instruments are used in Armenian folk music?
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A: the duduk, the dhol, the zurna and the kanun


Problem: Queen (band):

In late 1975, Queen recorded and released A Night at the Opera, taking its name from the popular Marx Brothers movie. At the time, it was the most expensive album ever produced. Like its predecessor, the album features diverse musical styles and experimentation with stereo sound. In "The Prophet's Song", an eight-minute epic, the middle section is a canon, with simple phrases layered to create a full-choral sound. The Mercury penned ballad, "Love of My Life", featured a harp and overdubbed vocal harmonies. The album was very successful in Britain, and went triple platinum in the United States. The British public voted it the 13th greatest album of all time in a 2004 Channel 4 poll. It has also ranked highly in international polls; in a worldwide Guinness poll, it was voted the 19th greatest of all time, while an ABC poll saw the Australian public vote it the 28th greatest of all time. A Night at the Opera has frequently appeared in "greatest albums" lists reflecting the opinions of critics. Among other accolades, it was ranked number 16 in Q Magazine's "The 50 Best British Albums Ever" in 2004, and number 11 in Rolling Stone's "The 100 Greatest Albums of All Time" as featured in their Mexican edition in 2004. It was also placed at No. 230 on Rolling Stone magazine's list of "The 500 Greatest Albums of All Time" in 2003. A Night at the Opera is the third and final Queen album to be featured in the book 1001 Albums You Must Hear Before You Die.

Which Queen album was released in 1975?
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A: A Night at the Opera


Problem: Planck constant:

There are both practical and theoretical difficulties in determining h. The practical difficulties can be illustrated by the fact that the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another. The most likely reason is that the measurement uncertainty for one (or both) of the methods has been estimated too low – it is (or they are) not as precise as is currently believed – but for the time being there is no indication which method is at fault.

Which method is at fault or the discrepancy?
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A:
there is no indication which method is at fault