Ключевые слова: background, black, chemical, clean, clear, color, corrosive, cream, crystal, danger, drop, education, environment, factory, glass, glove, hand, hot, industry, lab, laboratory, light, liquid, lump, manufacture, material, mix, new, newspaper, ph, research, safety, sample, science, silica, skin, small, sodium silicate, solid, solution, sticky, substance, symbol, test, top, view, water, wet, white,