Ключевые слова: air pollution, analyzing, concept, concepts, danger, dangerous, detective, discovery, environmental damage, environmental issues, examining, exploration, field, finding, gas, grass, grass area, ideas, land, lawn, magnifying glass, meadow, natures, periodic table, poisonous, radiation, radioactive contamination, radioactive warning symbol, radioactivity, radon gas, radon test, research, risk, searching, soil,