Areas may undergo pollution.Logical formLearned from11 sentences. An environmental pollution can be aggravated.Logical formLearned from11 sentences. Pollution can be in a lake.Logical formLearned from11 sentences. Pollution can be under control.Logical formLearned from11 sentences. An (air pollution) can be unhealthy.Logical formLearned from11 sentences. An environmental pollution can be urban.Logical formLearned from11 sentences. Progress can be in (pollution control).Logical formLearned from11 sentences. Degrees can be constituted-of-or-filled-with pollution.Logical formLearned from11 sentences. (Water pollution) may undergo a treatment.Logical formLearned from11 sentences. Risks can be constituted-of-or-filled-with pollution.Logical formLearned from11 sentences. Pollution can be a threat.Logical formLearned from11 sentences. Areas can be with pollution.Logical formLearned from11 sentences. Threats can be constituted-of-or-filled-with pollution.Logical formLearned from11 sentences. Pollution can be irreversible.Logical formLearned from11 sentences. Pollution may continue.Logical formLearned from11 sentences.