Problem: Frédéric Chopin:

Chopin also endowed popular dance forms with a greater range of melody and expression. Chopin's mazurkas, while originating in the traditional Polish dance (the mazurek), differed from the traditional variety in that they were written for the concert hall rather than the dance hall; "it was Chopin who put the mazurka on the European musical map." The series of seven polonaises published in his lifetime (another nine were published posthumously), beginning with the Op. 26 pair (published 1836), set a new standard for music in the form. His waltzes were also written specifically for the salon recital rather than the ballroom and are frequently at rather faster tempos than their dance-floor equivalents.

What was Chopin responsible for making popular with Euorpeans?
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A: the mazurka


Problem: The southern portion of the Point Loma peninsula was set aside for military purposes as early as 1852. Over the next several decades the Army set up a series of coastal artillery batteries and named the area Fort Rosecrans. Significant U.S. Navy presence began in 1901 with the establishment of the Navy Coaling Station in Point Loma, and expanded greatly during the 1920s. By 1930, the city was host to Naval Base San Diego, Naval Training Center San Diego, San Diego Naval Hospital, Camp Matthews, and Camp Kearny (now Marine Corps Air Station Miramar). The city was also an early center for aviation: as early as World War I, San Diego was proclaiming itself "The Air Capital of the West". The city was home to important airplane developers and manufacturers like Ryan Airlines (later Ryan Aeronautical), founded in 1925, and Consolidated Aircraft (later Convair), founded in 1923. Charles A. Lindbergh's plane The Spirit of St. Louis was built in San Diego in 1927 by Ryan Airlines.
What airplane developer was founded in San Diego in 1932?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The apparently sudden appearance of nearly modern flowers in the fossil record initially posed such a problem for the theory of evolution that it was called an "abominable mystery" by Charles Darwin. However, the fossil record has considerably grown since the time of Darwin, and recently discovered angiosperm fossils such as Archaefructus, along with further discoveries of fossil gymnosperms, suggest how angiosperm characteristics may have been acquired in a series of steps. Several groups of extinct gymnosperms, in particular seed ferns, have been proposed as the ancestors of flowering plants, but there is no continuous fossil evidence showing exactly how flowers evolved. Some older fossils, such as the upper Triassic Sanmiguelia, have been suggested. Based on current evidence, some propose that the ancestors of the angiosperms diverged from an unknown group of gymnosperms in the Triassic period (245–202 million years ago). Fossil angiosperm-like pollen from the Middle Triassic (247.2–242.0 Ma) suggests an older date for their origin. A close relationship between angiosperms and gnetophytes, proposed on the basis of morphological evidence, has more recently been disputed on the basis of molecular evidence that suggest gnetophytes are instead more closely related to other gymnosperms.[citation needed]
What was ancestors of angiosperms suddenly appearing called by Charles Darwin?
A: unanswerable


Context and question: Ion gauges are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the hot cathode version an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The current depends on the number of ions, which depends on the pressure in the gauge. Hot cathode gauges are accurate from 10−3 torr to 10−10 torr. The principle behind cold cathode version is the same, except that electrons are produced in a discharge created by a high voltage electrical discharge. Cold cathode gauges are accurate from 10−2 torr to 10−9 torr. Ionization gauge calibration is very sensitive to construction geometry, chemical composition of gases being measured, corrosion and surface deposits. Their calibration can be invalidated by activation at atmospheric pressure or low vacuum. The composition of gases at high vacuums will usually be unpredictable, so a mass spectrometer must be used in conjunction with the ionization gauge for accurate measurement.
Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement?
Answer: composition of gases at high vacuums will usually be unpredictable


Question: The rural Plains have lost a third of their population since 1920. Several hundred thousand square miles (several hundred thousand square kilometers) of the Great Plains have fewer than 6 inhabitants per square mile (2.3 inhabitants per square kilometer)—the density standard Frederick Jackson Turner used to declare the American frontier "closed" in 1893. Many have fewer than 2 inhabitants per square mile (0.77 inhabitants per square kilometer). There are more than 6,000 ghost towns in the state of Kansas alone, according to Kansas historian Daniel Fitzgerald. This problem is often exacerbated by the consolidation of farms and the difficulty of attracting modern industry to the region. In addition, the smaller school-age population has forced the consolidation of school districts and the closure of high schools in some communities. The continuing population loss has led some to suggest that the current use of the drier parts of the Great Plains is not sustainable, and there has been a proposal - the "Buffalo Commons" - to return approximately 139,000 square miles (360,000 km2) of these drier parts to native prairie land.
Is there an answer to this question: In what year was the "Buffalo Commons" proposal made?

Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
State law codifies Oklahoma's state emblems and honorary positions; the Oklahoma Senate or House of Representatives may adopt resolutions designating others for special events and to benefit organizations. Currently the State Senate is waiting to vote on a change to the state's motto. The House passed HCR 1024, which will change the state motto from "Labor Omnia Vincit" to "Oklahoma-In God We Trust!" The author of the resolution stated that a constituent researched the Oklahoma Constitution and found no "official" vote regarding "Labor Omnia Vincit", therefore opening the door for an entirely new motto.
What was Oklahoma's state motto, before the state House bill might change it?
A:
Labor Omnia Vincit