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These developments led to the theory of conservation of energy, formalized largely by William Thomson (Lord Kelvin) as the field of thermodynamics. Thermodynamics aided the rapid development of explanations of chemical processes by Rudolf Clausius, Josiah Willard Gibbs, and Walther Nernst. It also led to a mathematical formulation of the concept of entropy by Clausius and to the introduction of laws of radiant energy by Jozef Stefan. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time. Thus, since 1918, theorists have understood that the law of conservation of energy is the direct mathematical consequence of the translational symmetry of the quantity conjugate to energy, namely time.
since 1819, theorists have understood that the law of conservation of energy is what?
A: unanswerable

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Roman histories and biographies anticipated the extensive mediaeval literature of lives of saints and miraculous chronicles, but the most characteristic form of the Middle Ages was the romance, an adventurous and sometimes magical narrative with strong popular appeal. Controversial, religious, political and instructional literature proliferated during the Renaissance as a result of the invention of printing, while the mediaeval romance developed into a more character-based and psychological form of narrative, the novel, of which early and important examples are the Chinese Monkey and the German Faust books.
What are two late important examples of the novel?
A: unanswerable

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Finally, on 26 June, four days after France sued for an armistice with the Third Reich, the Soviet Union issued an ultimatum demanding Bessarabia and, unexpectedly, Northern Bukovina from Romania. Two days later, the Romanians caved to the Soviet demands and the Soviets occupied the territory. The Hertza region was initially not requested by the USSR but was later occupied by force after the Romanians agreed to the initial Soviet demands. The subsequent waves of deportations began in Bessarabia and Northern Bukovina.
What month did France sue for peace?
A: June

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During the September 11, 2001 attacks on the World Trade Center, FBI agent Leonard W. Hatton Jr. was killed during the rescue effort while helping the rescue personnel evacuate the occupants of the South Tower and stayed when it collapsed. Within months after the attacks, FBI Director Robert Mueller, who had been sworn in a week before the attacks, called for a re-engineering of FBI structure and operations. He made countering every federal crime a top priority, including the prevention of terrorism, countering foreign intelligence operations, addressing cyber security threats, other high-tech crimes, protecting civil rights, combating public corruption, organized crime, white-collar crime, and major acts of violent crime.
What FBI agent was killed during attacks on the World Trade Center?
A:
Leonard W. Hatton Jr