Ключевые слова: acid, alkaline, analysis, base, checking, chemical, chemicals, chemicstry, chemistry, chlorine, clean, cleaner, color, environment, hand, hold, holding, home, indicator, kit, lab, laboratory, maintenance, measure, orange, paper, ph, pool, reaction, red, scale, science, sciencetific, sciencetist, service, swimming, test, testing, tube, water, white, yellow,