All living organisms need metabolism, otherwise, life will stop. Civilization is the same. If it is self-closed for a long time, it will inevitably decline. Exchanges and mutual learning are the essential requirements for the development of civilization. The vitality of life. From this we can infer:. ['A civilization cannot maintain its vitality without exchanging knowledge with other civilizations.', 'A civilization will not decline unless it is self-closed for a long time.', "If a civilization communicates and learns from other civilizations and learns from each other's strengths, it can maintain its vitality.", 'If a civilization does not maintain its vigorous vitality, it will not learn from other civilizations.']