Problem: Franco-Prussian War:

The French breech-loading rifle, the Chassepot, had a far longer range than the German needle gun; 1,500 yards (1,400 m) compared to 600 yd (550 m). The French also had an early machine-gun type weapon, the mitrailleuse, which could fire its thirty-seven barrels at a range of around 1,200 yd (1,100 m). It was developed in such secrecy, that little training with the weapon had occurred, leaving French gunners with no experience; the gun was treated like artillery and in this role it was ineffective. Worse still, once the small number of soldiers who had been trained how to use the new weapon became casualties, there were no replacements who knew how to operate the mitrailleuse.

Treating the mitrailleuse like what rendered it far less effective
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A: artillery

Problem: Law of the United States:

Notably, a statute does not disappear automatically merely because it has been found unconstitutional; it must be deleted by a subsequent statute. Many federal and state statutes have remained on the books for decades after they were ruled to be unconstitutional. However, under the principle of stare decisis, no sensible lower court will enforce an unconstitutional statute, and any court that does so will be reversed by the Supreme Court. Conversely, any court that refuses to enforce a constitutional statute (where such constitutionality has been expressly established in prior cases) will risk reversal by the Supreme Court.

How long does it take for the principle of stare decisis to come into affect?
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A: unanswerable

Problem: Paris:

The Metropole du Grand Paris, or Metropolis of Greater Paris, formally came into existence on January 1, 2016. It is an administrative structure for cooperation between the City of Paris and its nearest suburbs. It includes the City of Paris, plus the communes, or towns of the three departments of the inner suburbs; Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne; plus seven communes in the outer suburbs, including Argenteuil in Val d'Oise and Paray-Vieille-Poste in Essonne, which were added to include the major airports of Paris. The Metropole covers 814 square kilometers and has a population of 6.945 million persons.

What is the population of the metropole?
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A: 6.945 million

Problem: Ottoman Empire:

As the Ottoman Empire gradually shrank in size, some 79 million Turkish-Muslims from its former territories in the Caucasus, Crimea, Balkans, and the Mediterranean islands migrated to Anatolia and Eastern Thrace. After the Empire lost the Balkan Wars (191213), it lost all its Balkan territories except East Thrace (European Turkey). This resulted in around 400,000 Muslims fleeing with the retreating Ottoman armies (with many dying from cholera brought by the soldiers), and with some 400,000 non-Muslims fleeing territory still under Ottoman rule. Justin McCarthy estimates that during the period 1821 to 1922 several million Muslims died in the Balkans, with the expulsion of a similar number.

When did the Balkan Wars take place?
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A:
191213