Please answer this: Background: Naturally occurring uranium is composed almost entirely of two isotopes, uranium-238 (99%) and uranium-235 (1%). It is the uranium-235 that is fissionable (will undergo fission) and therefore, this is the uranium isotope than can be used for fuel in a nuclear reactor. For uranium to be used as fuel, the percent of uranium-235 must be increased to at least 3%. Uranium in which the U-235 content is more than 1% is called enriched uranium. Somehow, the two isotopes must be separated so that enriched uranium is available for use as fuel. Separating the isotope by chemical means (chemical reactions) is not successful because the isotopes have exactly the same chemistry. The only essential difference between U-238 and U-235 is their atomic masses; as a result, the two isotopes are separated by a physical means that takes advantage of the difference in mass. Paragraph: John is a nuclear scientist who works at the Fermi lab. Today, in front of him he has four samples, sample A, sample B, sample C, and sample D. Sample A is the naturally occurring uranium. Sample B is enriched uranium. Sample C is the U-238, and sample D is the U-235. He needs to figure out how to best use them. Given the paragraph above, please answer correctly the following question: Which smaple would not be fissionable, sample C or sample D?
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Answer: sample C

Please answer this: Background: "There is now unequivocal evidence that biodiversity loss reduces the efficiency by which ecological communities capture biologically essential resources, produce biomass, decompose and recycle biologically essential nutrients... There is mounting evidence that biodiversity increases the stability of ecosystem functions through time... Diverse communities are more productive because they contain key species that have a large influence on productivity and differences in functional traits among organisms increase total resource capture... The impacts of diversity loss on ecological processes might be sufficiently large to rival the impacts of many other global drivers of environmental change... Maintaining multiple ecosystem processes at multiple places and times requires higher levels of biodiversity than does a single process at a single place and time." Paragraph: Nicaragua is one of the most biodiverse countries in the Americas. They boast over five hundred species of birds, and thousands of species of plants. Across the pond in England the situation is completely different. Centuries of extensive farming, industrialization, and urban sprawls have made it one of the least biodiverse place on Earth. Given the paragraph above, please answer correctly the following question: Would the ecosystem functions be less or more stable in Nicaragua than in England?
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Answer: more

Please answer this: Background: Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death. Paragraph: Two brothers went to the doctor for their yearly examination. Liam found out he has high cholesterol, while Rudy found out his triglycerides and cholesterol are within normal parameters. Given the paragraph above, please answer correctly the following question: Which brother was less at risk for plaques that can restrict or even block the flow of blood?
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Answer:
Rudy