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Tajikistan means the "Land of the Tajiks". The suffix "-stan" (Persian: -stan) is Persian for "place of" or "country" and Tajik is, most likely, the name of a pre-Islamic (before the seventh century A.D.) tribe. According to the Library of Congress's 1997 Country Study of Tajikistan, it is difficult to definitively state the origins of the word "Tajik" because the term is "embroiled in twentieth-century political disputes about whether Turkic or Iranian peoples were the original inhabitants of Central Asia."
According to the Library of Congress's 1987 Country Study of Tajikistan, what is difficult?
A: unanswerable

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Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the finished photomask was photolithographically reproduced onto a photoresist coating on the blank copper-clad boards.
What did PCB designers used to employ on a mylar sheet?
A: photomask

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During the Risorgimento, proponents of Italian republicanism and Italian nationalism, such as Alessandro Manzoni, stressed the importance of establishing a uniform national language in order to better create an Italian national identity. With the unification of Italy in the 1860s, standard Italian became the official national language of the new Italian state, while the various unofficial regional languages of Italy gradually became regarded as subordinate "dialects" to Italian, increasingly associated negatively with lack of education or provincialism. However, at the time of the Italian Unification, standard Italian still existed mainly as a literary language, and only 2.5% of Italy's population could speak standard Italian.
During which decade was Italy de-unified?
A: unanswerable

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On December 13, 2013, Beyonce unexpectedly released her eponymous fifth studio album on the iTunes Store without any prior announcement or promotion. The album debuted atop the Billboard 200 chart, giving Beyonce her fifth consecutive number-one album in the US. This made her the first woman in the chart's history to have her first five studio albums debut at number one. Beyonce received critical acclaim and commercial success, selling one million digital copies worldwide in six days; The New York Times noted the album's unconventional, unexpected release as significant. Musically an electro-R&B album, it concerns darker themes previously unexplored in her work, such as "bulimia, postnatal depression [and] the fears and insecurities of marriage and motherhood". The single "Drunk in Love", featuring Jay Z, peaked at number two on the Billboard Hot 100 chart. In April 2014, after much speculation in the weeks before, Beyonce and Jay Z officially announced their On the Run Tour. It served as the couple's first co-headlining stadium tour together. On August 24, 2014, she received the Video Vanguard Award at the 2014 MTV Video Music Awards. Knowles also took home three competitive awards: Best Video with a Social Message and Best Cinematography for "Pretty Hurts", as well as best collaboration for "Drunk in Love". In November, Forbes reported that Beyonce was the top-earning woman in music for the second year in a rowearning $115 million in the year, more than double her earnings in 2013. Beyonce was reissued with new material in three forms: as an extended play, a box set, as well as a full platinum edition.
Who joined Beyonce on her On The Run Tour?
A:
Jay Z