Environmental problems can be serious.Logical formLearned from512 sentences. A US-city may have a problem.Logical formLearned from512 sentences. (Health problems) can be long-term.Logical formLearned from511 sentences. Variety can be constituted-of-or-filled-with (health problems).Logical formLearned from509 sentences. Problems can be daily.Logical formLearned from509 sentences. A problem can be persons.Logical formLearned from506 sentences. A problem can be widespread.Logical formLearned from503 sentences. Problems may pertain-to life.Logical formLearned from502 sentences. Problems can be unanticipated.Logical formLearned from502 sentences. A male may solve a problem.Logical formLearned from500 sentences. A person may encounter a problem.Logical formLearned from499 sentences. Problems can be with a country.Logical formLearned from496 sentences. A problem may grow.Logical formLearned from495 sentences. A problem can be perceived.Logical formLearned from494 sentences. Problems can be in a continent.Logical formLearned from493 sentences.