Question: Oklahoma has four primary mountain ranges: the Ouachita Mountains, the Arbuckle Mountains, the Wichita Mountains, and the Ozark Mountains. Contained within the U.S. Interior Highlands region, the Ozark and Ouachita Mountains mark the only major mountainous region between the Rocky Mountains and the Appalachians. A portion of the Flint Hills stretches into north-central Oklahoma, and near the state's eastern border, Cavanal Hill is regarded by the Oklahoma Tourism & Recreation Department as the world's tallest hill; at 1,999 feet (609 m), it fails their definition of a mountain by one foot.
Is there an answer to this question: What part of Oklahoma does the Flint Hills reach into?

Answer: north-central


Question: When Estonia was invaded and occupied by the Soviet Union in World War II, the status of the Estonian language changed to the first of two official languages (Russian being the other one). As with Latvia many immigrants entered Estonia under Soviet encouragement. In the second half of the 1970s, the pressure of bilingualism (for Estonians) intensified, resulting in widespread knowledge of Russian throughout the country. The Russian language was termed as ‘the language of friendship of nations’ and was taught to Estonian children, sometimes as early as in kindergarten. Although teaching Estonian to non-Estonians in schools was compulsory, in practice learning the language was often considered unnecessary.
Is there an answer to this question: What is the third language of Estonia? 

Answer: unanswerable


Question: Mining was important in Thuringia since the later Middle Ages, especially within the mining towns of the Thuringian Forest such as Schmalkalden, Suhl and Ilmenau. Following the industrial revolution, the old iron, copper and silver mines declined because the competition from imported metal was too strong. On the other hand, the late 19th century brought new types of mines to Thuringia: the lignite surface mining around Meuselwitz near Altenburg in the east of the Land started in the 1870s, and two potash mining districts were established around 1900. These are the Südharzrevier in the north of the state, between Bischofferode in the west and Roßleben in the east with Sondershausen at its centre, and the Werrarevier on the Hessian border around Vacha and Bad Salzungen in the west. Together, they accounted for a significant part of the world's potash production in the mid-20th century. After the reunification, the Südharzrevier was abandoned, whereas K+S took over the mines in the Werrarevier. Between 1950 and 1990, uranium mining was also important to cover the Soviet Union's need for this metal. The centre was Ronneburg near Gera in eastern Thuringia and the operating company Wismut was under direct Soviet control.
Is there an answer to this question: When did the Südharzrevier close?

Answer: After the reunification


Question: A revolution in 1332 resulted in a broad-based city government with participation of the guilds, and Strasbourg declared itself a free republic. The deadly bubonic plague of 1348 was followed on 14 February 1349 by one of the first and worst pogroms in pre-modern history: over a thousand Jews were publicly burnt to death, with the remainder of the Jewish population being expelled from the city. Until the end of the 18th century, Jews were forbidden to remain in town after 10 pm. The time to leave the city was signalled by a municipal herald blowing the Grüselhorn (see below, Museums, Musée historique);. A special tax, the Pflastergeld (pavement money), was furthermore to be paid for any horse that a Jew would ride or bring into the city while allowed to.
Is there an answer to this question: How many Jewish people avoided being publicly burnt to death?

Answer:
unanswerable