The problem: Answer a question about this article:
Bern has an area, as of 2009[update], of 51.62 square kilometers (19.93 sq mi). Of this area, 9.79 square kilometers (3.78 sq mi) or 19.0% is used for agricultural purposes, while 17.33 square kilometers (6.69 sq mi) or 33.6% is forested. Of the rest of the land, 23.25 square kilometers (8.98 sq mi) or 45.0% is settled (buildings or roads), 1.06 square kilometers (0.41 sq mi) or 2.1% is either rivers or lakes and 0.16 square kilometers (0.062 sq mi) or 0.3% is unproductive land.
What is 33.6% of the land in Bern?
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The answer: forested

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One of the most important developments that the Enlightenment era brought to the discipline of science was its popularization. An increasingly literate population seeking knowledge and education in both the arts and the sciences drove the expansion of print culture and the dissemination of scientific learning. The new literate population was due to a high rise in the availability of food. This enabled many people to rise out of poverty, and instead of paying more for food, they had money for education. Popularization was generally part of an overarching Enlightenment ideal that endeavoured "to make information available to the greatest number of people." As public interest in natural philosophy grew during the 18th century, public lecture courses and the publication of popular texts opened up new roads to money and fame for amateurs and scientists who remained on the periphery of universities and academies. More formal works included explanations of scientific theories for individuals lacking the educational background to comprehend the original scientific text. Sir Isaac Newton's celebrated Philosophiae Naturalis Principia Mathematica was published in Latin and remained inaccessible to readers without education in the classics until Enlightenment writers began to translate and analyze the text in the vernacular.
Instead of paying more for food, on what did people spend their money?
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The answer: education

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The Classical era stringed instruments were the four instruments which form the string section of the orchestra: the violin, viola, cello and contrabass. Woodwinds included the basset clarinet, basset horn, clarinette d'amour, the Classical clarinet, the chalumeau, the flute, oboe and bassoon. Keyboard instruments included the clavichord and the fortepiano. While the harpsichord was still used in basso continuo accompaniment in the 1750s and 1760s, it fell out of use in the end of the century. Brass instruments included the buccin, the ophicleide (a serpent replacement which was the precursor of tuba) and the natural horn.
What instrument was the precursor of the tuba?
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The answer: the ophicleide

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The Late Middle Ages represented a period of upheaval in Europe. The epidemic known as the Black Death and an associated famine caused demographic catastrophe in Europe as the population plummeted. Dynastic struggles and wars of conquest kept many of the states of Europe at war for much of the period. In the Balkans, the Ottoman Empire, a Turkish state originating in Anatolia, encroached steadily on former Byzantine lands, culminating in the Fall of Constantinople in 1453.
When did the Ottoman Empire conquer Constantinople?
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The answer:
1453