In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Q: Which of the following did not occur in the 20th century: urbanization, the spread of the Ottoman Empire, or wars?, Context: South Slavic historically formed a dialect continuum, i.e. each dialect has some similarities with the neighboring one, and differences grow with distance. However, migrations from the 16th to 18th centuries resulting from the spread of Ottoman Empire on the Balkans have caused large-scale population displacement that broke the dialect continuum into many geographical pockets. Migrations in the 20th century, primarily caused by urbanization and wars, also contributed to the reduction of dialectal differences.

A: spread of Ottoman Empire
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Q: Who were the communists that came to power?, Context: Following the breakup of the Russian Empire in the aftermath of World War I for a brief period, from 1918 to 1920, Armenia was an independent republic. In late 1920, the communists came to power following an invasion of Armenia by the Red Army, and in 1922, Armenia became part of the Transcaucasian SFSR of the Soviet Union, later forming the Armenian Soviet Socialist Republic (1936 to September 21, 1991). In 1991, Armenia declared independence from the USSR and established the second Republic of Armenia.

A: Transcaucasian SFSR of the Soviet Union
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Q: Where does water transform inside a light bulb?, Context: A very small amount of water vapor inside a light bulb can significantly affect lamp darkening. Water vapor dissociates into hydrogen and oxygen at the hot filament. The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp. Hydrogen from water vapor reduces the oxide, reforming water vapor and continuing this water cycle. The equivalent of a drop of water distributed over 500,000 lamps will significantly increase darkening. Small amounts of substances such as zirconium are placed within the lamp as a getter to react with any oxygen that may bake out of the lamp components during operation.

A:
filament
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