A river may undergo pollution.Logical formLearned from242 sentences. An (air pollution) may pertain-to a world-city.Logical formLearned from242 sentences. Sources can be constituted-of-or-filled-with (air pollution).Logical formLearned from232 sentences. A source can be constituted-of-or-filled-with (air pollution).Logical formLearned from212 sentences. Pollution can be indoor.Logical formLearned from210 sentences. Pollution can be particulate.Logical formLearned from208 sentences. Pollution can be global.Logical formLearned from202 sentences. An (air pollution) can be particulate.Logical formLearned from194 sentences. Pollution can be a problem.Logical formLearned from190 sentences. (Air pollution) can be in a world-city.Logical formLearned from188 sentences. Pollution can be man-made.Logical formLearned from184 sentences. (Pollution problems) can be serious.Logical formLearned from183 sentences. Pollution may pertain-to a city.Logical formLearned from183 sentences. Pollution may pertain-to a country.Logical formLearned from181 sentences. Exposure can be to (air pollution).Logical formLearned from180 sentences.