Problem: Glass:

The most familiar, and historically the oldest, types of glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. The term glass, in popular usage, is often used to refer only to this type of material, which is familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives. A very clear and durable quartz glass can be made from pure silica, but the high melting point and very narrow glass transition of quartz make glassblowing and hot working difficult. In glasses like soda lime, the compounds added to quartz are used to lower the melting temperature and improve workability, at a cost in the toughness, thermal stability, and optical transmittance.

What is sand mostly made of?
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A: silica


Problem: Cuba, like many Spanish territories, wanted to break free from Spain. A pro-independence movement in Cuba was supported by the U.S., and Cuban guerrilla leaders wanted annexation to the United States, but Cuban revolutionary leader José Martí called for Cuban nationhood. When the U.S. battleship Maine sank in Havana Harbor, the U.S. blamed Spain and the Spanish–American War broke out in 1898. After the U.S. won, Spain relinquished claim of sovereignty over territories, including Cuba. The U.S. administered Cuba as a protectorate until 1902. Several decades later in 1959, the corrupt Cuban government of U.S.-backed Fulgencio Batista was overthrown by Fidel Castro. Castro installed a Marxist–Leninist government allied with the Soviet Union, which has been in power ever since.
What government did Castro install?
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Answer: Marxist–Leninist government


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The immediate nationwide uprisings against the new government began by the 1979 Kurdish rebellion with the Khuzestan uprisings, along with the uprisings in Sistan and Baluchestan Province and other areas. Over the next several years, these uprisings were subdued in a violent manner by the new Islamic government. The new government went about purging itself of the non-Islamist political opposition. Although both nationalists and Marxists had initially joined with Islamists to overthrow the Shah, tens of thousands were executed by the Islamic government afterward.
The new Iranian government following the Shah's downfall dealt with the Kurdish rebellion in what year?
A: 1979


Context and question: In the 20th century, Russian was mandatorily taught in the schools of the members of the old Warsaw Pact and in other countries that used to be satellites of the USSR. In particular, these countries include Poland, Bulgaria, the Czech Republic, Slovakia, Hungary, Albania, former East Germany and Cuba. However, younger generations are usually not fluent in it, because Russian is no longer mandatory in the school system. According to the Eurobarometer 2005 survey, though, fluency in Russian remains fairly high (20–40%) in some countries, in particular those where the people speak a Slavic language and thereby have an edge in learning Russian (namely, Poland, Czech Republic, Slovakia, and Bulgaria).
What is the fluency in Polish in some countries according to the Eurobarometer?
Answer: unanswerable


Question: The Ottoman Empire or, as a dynastic institution, the House of Osman was unprecedented and unequaled in the Islamic world for its size and duration. In Europe, only the House of Habsburg had a similarly unbroken line of sovereigns (kings/emperors) from the same family who ruled for so long, and during the same period, between the late 13th and early 20th centuries. The Ottoman dynasty was Turkish in origin. On eleven occasions, the sultan was deposed (replaced by another sultan of the Ottoman dynasty, who were either the former sultan's brother, son or nephew) because he was perceived by his enemies as a threat to the state. There were only two attempts in Ottoman history to unseat the ruling Ottoman dynasty, both failures, which suggests a political system that for an extended period was able to manage its revolutions without unnecessary instability. As such, the last Ottoman sultan Mehmed VI (r. 1918–1922) was a direct patrilineal (male-line) descendant of the first Ottoman sultan Osman I (r. 1299–1326), which was unparallelled in both Europe (e.g. the male line of the House of Habsburg became extinct in 1740) and in the Islamic world. The primary purpose of the Imperial Harem was to ensure the birth of male heirs to the Ottoman throne and secure the continuation of the direct patrilineal (male-line) descendance of the Ottoman sultans.
Is there an answer to this question: What was another name for the Ottoman Empire?

Answer: House of Osman


Sanskrit, as defined by Pāṇini, evolved out of the earlier Vedic form. The present form of Vedic Sanskrit can be traced back to as early as the second millennium BCE (for Rig-vedic). Scholars often distinguish Vedic Sanskrit and Classical or "Pāṇinian" Sanskrit as separate dialects. Though they are quite similar, they differ in a number of essential points of phonology, vocabulary, grammar and syntax. Vedic Sanskrit is the language of the Vedas, a large collection of hymns, incantations (Samhitas) and theological and religio-philosophical discussions in the Brahmanas and Upanishads. Modern linguists consider the metrical hymns of the Rigveda Samhita to be the earliest, composed by many authors over several centuries of oral tradition. The end of the Vedic period is marked by the composition of the Upanishads, which form the concluding part of the traditional Vedic corpus; however, the early Sutras are Vedic, too, both in language and content.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): As what are Classical and Vedic Sanskrit often viewed?
Ah, so..
separate dialects