Concepts may be considered.Logical formLearned from26 sentences. A concept may be taught.Logical formLearned from26 sentences. A concept can be useless.Logical formLearned from26 sentences. Concepts may pertain-to a language.Logical formLearned from26 sentences. Students may grasp concepts.Logical formLearned from26 sentences. Persons may develop concepts.Logical formLearned from26 sentences. Concepts can be tactical.Logical formLearned from26 sentences. A (security concept) can be tried.Logical formLearned from26 sentences. A (security concept) can be during an european (football championship).Logical formLearned from26 sentences. A concept may pertain-to a model.Logical formLearned from26 sentences. A concept can be for a country.Logical formLearned from25 sentences. A concept can be constituted-of-or-filled-with time.Logical formLearned from25 sentences. A distinction can be between some concepts.Logical formLearned from25 sentences. A concept may be originated.Logical formLearned from25 sentences. A (development concept) can be sustainable.Logical formLearned from25 sentences.