In the process of symbiosis between human and other species in nature, they depend on the universe, sunlight, water, air and other materials for reproduction and evolution. For hundreds of thousands of years, man lived in the sun, the light of the moon, and the fire of the fire. During the day, humans enjoy the white glow of the bright sun; In the evening and at night, in the sunset sunset and the campfire human again under the high color warm yellow light. In this environment, human beings evolved from ancient times hundreds of thousands of years ago to today's highly civilized society.