uv Blue/Violet: 360-400nm(billionth); blue light -> cataract? 1 mile=5280 ft; 7=37K ft airplanes.
ozone O₂ 21%. HFC and PFC greenhouse, Propane hydrocarbon flammable Ozone hole peaks over Antarctica (2008)
cfc Aerosol: liquid evaporates -> gas; CFC also release fluorine; stratosphere 11-50km mesosphere
scientific FALSIFIABLE: coins. Dragonflies that cross oceans: simple observations lead to breathtaking discoveries
observational independent variable=X (abscissa)
control BUT careful: mice make their own ascorbate (vitamin C).
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