This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Ex Input:
Passage: The Treaty of Paris stood until 1871, when France was defeated by Prussia in the Franco-Prussian War of 18701871. While Prussia and several other German states united to form a powerful German Empire, the Emperor of the French, Napoleon III, was deposed to permit the formation of a Third French Republic. During his reign, Napoleon III, eager for the support of the United Kingdom, had opposed Russia over the Eastern Question. Russian interference in the Ottoman Empire, however, did not in any significant manner threaten the interests of France. Thus, France abandoned its opposition to Russia after the establishment of a republic. Encouraged by the decision of the French, and supported by the German minister Otto von Bismarck, Russia renounced the Black Sea clauses of the treaty agreed to in 1856. As the United Kingdom alone could not enforce the clauses, Russia once again established a fleet in the Black Sea. Question: Between what years did the Franco-Prussian War take place?

Ex Output:
18701871

Ex Input:
Passage: An electromagnetic wave refractor in some aperture antennas is a component which due to its shape and position functions to selectively delay or advance portions of the electromagnetic wavefront passing through it. The refractor alters the spatial characteristics of the wave on one side relative to the other side. It can, for instance, bring the wave to a focus or alter the wave front in other ways, generally in order to maximize the directivity of the antenna system. This is the radio equivalent of an optical lens. Question: What is used to allow one to control the function of wave fronts moving through an antenna?

Ex Output:
selectively delay

Ex Input:
Passage: In 1348, the Black Death and other disasters sealed a sudden end to the previous period of massive philosophic and scientific development. Yet, the rediscovery of ancient texts was improved after the Fall of Constantinople in 1453, when many Byzantine scholars had to seek refuge in the West. Meanwhile, the introduction of printing was to have great effect on European society. The facilitated dissemination of the printed word democratized learning and allowed a faster propagation of new ideas. New ideas also helped to influence the development of European science at this point: not least the introduction of Algebra. These developments paved the way for the Scientific Revolution, which may also be understood as a resumption of the process of scientific inquiry, halted at the start of the Black Death. Question: The invention of printing improved which society?

Ex Output:
European