Problem: As of September 2012, fifty-six species have been delisted; twenty-eight due to recovery, ten due to extinction (seven of which are believed to have been extinct prior to being listed), ten due to changes in taxonomic classification practices, six due to discovery of new populations, one due to an error in the listing rule, and one due to an amendment to the Endangered Species Act specifically requiring the species delisting. Twenty-five others have been down listed from "endangered" to "threatened" status.
How many species have recovered since 2012 due to changes?
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Answer: unanswerable

Problem: The heavy infantry of the maniples were supported by a number of light infantry and cavalry troops, typically 300 horsemen per manipular legion. The cavalry was drawn primarily from the richest class of equestrians. There was an additional class of troops who followed the army without specific martial roles and were deployed to the rear of the third line. Their role in accompanying the army was primarily to supply any vacancies that might occur in the maniples. The light infantry consisted of 1,200 unarmoured skirmishing troops drawn from the youngest and lower social classes. They were armed with a sword and a small shield, as well as several light javelins.
How many horseman were likely to be found in a single manipular legion?
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Answer: 300 horsemen

Problem: Kievan Rus' also played an important genealogical role in European politics. Yaroslav the Wise, whose stepmother belonged to the Macedonian dynasty, the greatest one to rule Byzantium, married the only legitimate daughter of the king who Christianized Sweden. His daughters became queens of Hungary, France and Norway, his sons married the daughters of a Polish king and a Byzantine emperor (not to mention a niece of the Pope), while his granddaughters were a German Empress and (according to one theory) the queen of Scotland. A grandson married the only daughter of the last Anglo-Saxon king of England. Thus the Rurikids were a well-connected royal family of the time.
Who did Yaroslav's sons marry?
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Answer:
daughters of a Polish king and a Byzantine emperor