Air may undergo concentration.Logical formLearned from4 sentences. Concentration can be over a shift.Logical formLearned from4 sentences. A capital may undergo concentration.Logical formLearned from4 sentences. Atomic oxygen may undergo concentration.Logical formLearned from4 sentences. Opportunities can be for concentration.Logical formLearned from4 sentences. Active compounds may undergo concentrations.Logical formLearned from4 sentences. Significant differences can be in concentration.Logical formLearned from4 sentences. Suspended sediments may undergo concentration.Logical formLearned from4 sentences. (Air concentration) can be constituted-of-or-filled-with toxic substances.Logical formLearned from4 sentences. Concentration can be in a home.Logical formLearned from4 sentences. Concentration can be in geology.Logical formLearned from4 sentences. (Carbonate ions) may undergo concentration.Logical formLearned from4 sentences. An oxygen may undergo concentrations.Logical formLearned from4 sentences. Concentrations of some oxygen may be determined.Logical formLearned from4 sentences. (Nitrogen compounds) may undergo concentrations.Logical formLearned from4 sentences.