The problem: Answer a question about this article:
Islamic architecture began in the 7th century CE, incorporating architectural forms from the ancient Middle East and Byzantium, but also developing features to suit the religious and social needs of the society. Examples can be found throughout the Middle East, North Africa, Spain and the Indian Sub-continent. The widespread application of the pointed arch was to influence European architecture of the Medieval period.
What other parts of the society's needs did architecture fill?
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The answer: religious and social needs

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The breakup of the Carolingian Empire was accompanied by invasions, migrations, and raids by external foes. The Atlantic and northern shores were harassed by the Vikings, who also raided the British Isles and settled there as well as in Iceland. In 911, the Viking chieftain Rollo (d. c. 931) received permission from the Frankish King Charles the Simple (r. 898922) to settle in what became Normandy.[Q] The eastern parts of the Frankish kingdoms, especially Germany and Italy, were under continual Magyar assault until the invader's defeat at the Battle of Lechfeld in 955. The breakup of the Abbasid dynasty meant that the Islamic world fragmented into smaller political states, some of which began expanding into Italy and Sicily, as well as over the Pyrenees into the southern parts of the Frankish kingdoms.
Who was king of the Franks in 899?
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The answer: Charles the Simple

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The botanical term "Angiosperm", from the Ancient Greek , angeion (bottle, vessel) and , (seed), was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked. The term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any approach to its modern scope became possible only after 1827, when Robert Brown established the existence of truly naked ovules in the Cycadeae and Coniferae, and applied to them the name Gymnosperms.[citation needed] From that time onward, as long as these Gymnosperms were, as was usual, reckoned as dicotyledonous flowering plants, the term Angiosperm was used antithetically by botanical writers, with varying scope, as a group-name for other dicotyledonous plants.
What did Robert Brown establish the existence of in Cycadeae and Coniferae?
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The answer: naked ovules

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Up to February 28 in the calendar you are converting from add one day less or subtract one day more than the calculated value. Remember to give February the appropriate number of days for the calendar you are converting into. When you are subtracting days to move from Julian to Gregorian be careful, when calculating the Gregorian equivalent of February 29 (Julian), to remember that February 29 is discounted. Thus if the calculated value is -4 the Gregorian equivalent of this date is February 24.
If you need a date of four days less, what do you subtract from the Julian calendar?
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The answer:
-4