Separate different images to make the language clearer. "Whistle in the mountains, fish swim at the bottom of the pool, camels walk in the desert and geese fly in the sky" comes from the language of nature. This sentence is separated by commas, which makes the four images of "whistling in the mountains", "swimming in the bottom of the pool", "camel walking in the desert" and "flying geese in the sky" more vivid, and makes readers understand the artistic conception that the author wants to express more clearly. At the same time, the use of commas also enhances the sense of rhythm and rhythm of the language.