Problem: Uranium:

In nature, uranium is found as uranium-238 (99.2742%) and uranium-235 (0.7204%). Isotope separation concentrates (enriches) the fissionable uranium-235 for nuclear weapons and most nuclear power plants, except for gas cooled reactors and pressurised heavy water reactors. Most neutrons released by a fissioning atom of uranium-235 must impact other uranium-235 atoms to sustain the nuclear chain reaction. The concentration and amount of uranium-235 needed to achieve this is called a 'critical mass'.

Along with gas heated reactors, what type of reactor doesn't use uranium-235?
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A: unanswerable

Problem: Hunter-gatherer:

Hunter-gatherers would eventually flourish all over the Americas, primarily based in the Great Plains of the United States and Canada, with offshoots as far east as the Gaspe Peninsula on the Atlantic coast, and as far south as Chile, Monte Verde.[citation needed] American hunter-gatherers were spread over a wide geographical area, thus there were regional variations in lifestyles. However, all the individual groups shared a common style of stone tool production, making knapping styles and progress identifiable. This early Paleo-Indian period lithic reduction tool adaptations have been found across the Americas, utilized by highly mobile bands consisting of approximately 25 to 50 members of an extended family.

Hunter-gatherers would never flourish over the what?
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A: unanswerable

Problem: Tibet:

Tibet retained nominal power over religious and regional political affairs, while the Mongols managed a structural and administrative rule over the region, reinforced by the rare military intervention. This existed as a "diarchic structure" under the Yuan emperor, with power primarily in favor of the Mongols. Mongolian prince Khuden gained temporal power in Tibet in the 1240s and sponsored Sakya Pandita, whose seat became the capital of Tibet. Drogon Chogyal Phagpa, Sakya Pandita's nephew became Imperial Preceptor of Kublai Khan, founder of the Yuan dynasty.

Who managed structural and administrative rule?
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A: Mongols

Problem: 2008 Sichuan earthquake:

In 2002, Chinese geologist Chen Xuezhong published a Seismic Risk Analysis study in which he came to the conclusion that beginning with 2003, attention should be paid to the possibility of an earthquake with a magnitude of over 7.0 occurring in Sichuan region. He based his study on statistical correlation. That Sichuan is a seismically active area has been discussed for years prior to the quake, though few studies point to a specific date and time.

When was a Seismic Risk Analysis published?
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A:
In 2002