Here is a question about this article: There are several sources of the seedlessness trait, and essentially all commercial cultivators get it from one of three sources: Thompson Seedless, Russian Seedless, and Black Monukka, all being cultivars of Vitis vinifera. There are currently more than a dozen varieties of seedless grapes. Several, such as Einset Seedless, Benjamin Gunnels's Prime seedless grapes, Reliance, and Venus, have been specifically cultivated for hardiness and quality in the relatively cold climates of northeastern United States and southern Ontario.
What is the answer to this question: How many seedless grape sources are there for commercial cultivators?
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So... three

Here is a question about this article: In 2014, the airport received 15 new boarding bridges, totalling 28 in all. This was the main requirement made by the federal government, which transferred the operation of the terminal to the Inframerica Group after an auction. The group invested R$750 million in the project. In the same year, the number of parking spaces doubled, reaching three thousand. The airport's entrance have a new rooftop cover and a new access road. Furthermore, a VIP room was created on Terminal 1's third floor. The investments resulted an increase the capacity of Brasilia's airport from approximately 15 million passengers per year to 21 million by 2014. Brasilia has direct flights to all states of Brazil and direct international flights to Atlanta, Buenos Aires, Lisbon, Miami, Panama City, and Paris.
What is the answer to this question: When did the number of boarding bridges at Brasilia's airport nearly double?
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So... 2014

Here is a question about this article: The Bulgarian Empire was in decline by the 14th century, and the ascendancy of Serbia was marked by the Serbian victory over the Bulgarians in the Battle of Velbazhd in 1330. By 1346, the Serbian king Stefan Dusan had been proclaimed emperor. Yet Serbian dominance was short-lived; the Serbian army led by the Lazar Hrebljevanovic was defeated by the Ottomans at the Battle of Kosovo in 1389, where most of the Serbian nobility was killed and the south of the country came under Ottoman occupation, as much of southern Bulgaria had become Ottoman territory in 1371. Northern remnants of Bulgaria were finally conquered by 1396, Serbia fell in 1459, Bosnia in 1463, and Albania was finally subordinated in 1479 only a few years after the death of Skanderbeg. Belgrade, an Hungarian domain at the time, was the last large Balkan city to fall under Ottoman rule, in 1521. By the end of the medieval period, the entire Balkan peninsula was annexed by, or became vassal to, the Ottomans.
What is the answer to this question: In what year was the Battle of Kosovo?
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So...
1389