In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Q: who avenged Chu'Tsai's forefathers?, Context: Genghis Khan realised that he needed people who could govern cities and states conquered by him. He also realised that such administrators could not be found among his Mongol people because they were nomads and thus had no experience governing cities. For this purpose Genghis Khan invited a Khitan prince, Chu'Tsai, who worked for the Jin and had been captured by the Mongol army after the Jin dynasty was defeated. Jin had captured power by displacing Khitan. Genghis told Chu'Tsai, who was a lineal descendant of Khitan rulers, that he had avenged Chu'Tsai's forefathers. Chu'Tsai responded that his father served the Jin dynasty honestly and so did he; also he did not consider his own father his enemy, so the question of revenge did not apply. This reply impressed Genghis Khan. Chu'Tsai administered parts of the Mongol Empire and became a confidant of the successive Mongol Khans.

A: Genghis Khan
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Q: What is the name of the discipline of the person Gregory of Tours reads?, Context: Even as the Western Roman empire collapsed, literate men acknowledged that Virgil was a master poet. Gregory of Tours read Virgil, whom he quotes in several places, along with some other Latin poets, though he cautions that "we ought not to relate their lying fables, lest we fall under sentence of eternal death."

A: poet
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Q: What does Coulomb's law concern itself with?, Context: QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.

A:
vacuum fluctuations
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