Question 20) The correct answer is: [B]:
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Thermal pollution is:
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[B]: "When water is used in industry to cool mechanisms such as a nuclear power plant; then the warmer water is released back into the ecosystem" .
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(and as such; the warmer water harms the ecosystem—aquatic life forms and other life forms & disrupts the ecosystem).
Note: By no means is this limited to a nuclear power plant. This can be a municipal wastewater treatment plant.
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Question 21) : "The best way to deal with groundwater pollution is to avoid letting it happen to start with." ANSWER: "TRUE" . {In the sense of taking steps to prevent groundwater pollution from further happening where it has not happened yet. Note that groundwater pollution is a point source of pollution; however, pollutants have a long mean residence time (i.e. stay there for a long time and are difficult to remove safely and effectively.).}.
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