A tint may be caused by iron.Logical formLearned from1 sentences. A tint may be caused by concentration of glass.Logical formLearned from1 sentences. A tint may be left by salts.Logical formLearned from1 sentences. Workers may wear glasses of a tint.Logical formLearned from1 sentences. Tints may be expressed by dots.Logical formLearned from1 sentences.