Every culture created by mankind is a dynamic living body, and various cultures come together to form various cultural communities, cultural circles, and even cultural chains similar to the food chain. They are interconnected into a dynamic life. The net, as an integral part of the human culture as a whole, has its own value and plays its role in maintaining the integrity of the entire human culture. What does the text mainly show? ['Human culture is essentially a dynamic life form.', 'The gathering of human culture is similar to an ecological system.', 'Human culture itself is like an ecosystem.', 'Human cultures are interconnected to form a dynamic network.']