Levels may pertain-to a substance.Logical formLearned from19 sentences. Some substances may be used.Logical formLearned from18 sentences. A substance can be philosophical.Logical formLearned from18 sentences. Substances may undergo an accumulation.Logical formLearned from18 sentences. (Blood levels) may pertain-to a substance.Logical formLearned from18 sentences. Substances can be in a diet.Logical formLearned from18 sentences. A substance may be absorbed.Logical formLearned from18 sentences. Response can be to substances.Logical formLearned from18 sentences. Changes can be in substance.Logical formLearned from18 sentences. A response may undergo a substance.Logical formLearned from18 sentences. Organic substances can be complex.Logical formLearned from18 sentences. A person may be exposed to a hazardous substance.Logical formLearned from18 sentences. Dependence can be on substances.Logical formLearned from18 sentences. A substance can be primitive.Logical formLearned from18 sentences. A substance can be deadly.Logical formLearned from18 sentences.