An (air pollution) may pertain-to a country.Logical formLearned from16 sentences. Pollution may remain a problem.Logical formLearned from16 sentences. A (runoff pollution) can be urban.Logical formLearned from16 sentences. A (water pollution) can be widespread.Logical formLearned from16 sentences. Emissions may contribute to (air pollution).Logical formLearned from16 sentences. A cap can be on pollution.Logical formLearned from16 sentences. A source can be constituted-of-or-filled-with (mercury pollution).Logical formLearned from16 sentences. Threats may include pollution.Logical formLearned from16 sentences. A component can be constituted-of-or-filled-with (air pollution).Logical formLearned from16 sentences. Protection can be against pollution.Logical formLearned from16 sentences. A solution can be to pollution.Logical formLearned from16 sentences. (Air pollution) may undergo a regulation.Logical formLearned from16 sentences. Pollution can be invisible.Logical formLearned from16 sentences. A city can be free from pollution.Logical formLearned from16 sentences. Pollution may be caused by humans.Logical formLearned from16 sentences.