(Air pollution standards) can be strict.Logical formLearned from6 sentences. (Noisier airports) may emit pollution.Logical formLearned from6 sentences. Developing countries may suffer from (air pollution problems).Logical formLearned from6 sentences. Pollution may be caused by flare_offing gas.Logical formLearned from6 sentences. A combination of pollution may tip scales.Logical formLearned from6 sentences. (Air pollution problems) can be chronic.Logical formLearned from6 sentences. A city can be with levels of (air pollution).Logical formLearned from6 sentences. (Air pollution) may cause some (health problems).Logical formLearned from6 sentences. A regime can be in reducing pollution.Logical formLearned from6 sentences. A proposal can be on (pollution quotas).Logical formLearned from6 sentences. A role may pertain-to (auto pollution).Logical formLearned from6 sentences. Health may be caused by (air pollution).Logical formLearned from6 sentences. A (pollution threat) can be serious.Logical formLearned from6 sentences. (Pollution levels) may reach highs.Logical formLearned from6 sentences. A (chemical pollution) can be organic.Logical formLearned from6 sentences.