"815" - 148 õppematerjali
815 - 4.287 ppm. The concentrations are mainly dependent on the age of the building, building materials, type of construction and ventilation.
Nagu näha, siis vastuse leidmine on päris raske, aga lendamine on hoopis imelihtne - tuleb vaid maa poole viskuda ja mööda kukkuda.
annaabi.ee 
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