Civilizations can be in a continent.Logical formLearned from21 sentences. Civilization may undergo an advancement.Logical formLearned from20 sentences. Civilization may undergo a building.Logical formLearned from20 sentences. Civilization may undergo ruins.Logical formLearned from20 sentences. A civilization can be extinct.Logical formLearned from20 sentences. A civilization can be industrialized.Logical formLearned from20 sentences. Civilizations can be dead.Logical formLearned from20 sentences. Contact can be with extraterrestrial civilizations.Logical formLearned from20 sentences. A country can be a cradle of civilization.Logical formLearned from20 sentences. A (civilization class) may pertain-to a person.Logical formLearned from20 sentences. A civilization can be prosperous.Logical formLearned from20 sentences. Civilizations can be playable.Logical formLearned from20 sentences. A period can be constituted-of-or-filled-with civilization.Logical formLearned from20 sentences. A civilization may undergo progress.Logical formLearned from20 sentences. A civilization can be in_trouble.Logical formLearned from20 sentences.