Elderly persons may undergo concentrations.Logical formLearned from5 sentences. Problems may undergo concentrations.Logical formLearned from5 sentences. Heavy metals may undergo concentration.Logical formLearned from5 sentences. Concentration can be reckless.Logical formLearned from5 sentences. (Power plants) may undergo concentrations.Logical formLearned from5 sentences. Concentrations can be in secondhand smoke.Logical formLearned from5 sentences. Cancer may undergo concentrations.Logical formLearned from5 sentences. Schools can be with concentrations of poverty.Logical formLearned from5 sentences. A stock may undergo concentrations.Logical formLearned from5 sentences. (Business ownership) may undergo concentrations.Logical formLearned from5 sentences. Hormone may undergo concentrations.Logical formLearned from5 sentences. Farming may undergo concentration.Logical formLearned from5 sentences. Concentrations of some ppb may cause abnormalities.Logical formLearned from5 sentences. Effects may be manifested at concentrations of atrazine.Logical formLearned from5 sentences. (Company stock) may undergo concentrations.Logical formLearned from5 sentences.