Sunflowers always face the sun, and the sun is round. Gu represents the number 0, which is symmetrical in two days. The number with this feature is 8, and the last running water indicates that water flows downwards, so it is the number 7. The habitats of wild sunflowers are mainly grasslands and dry and open areas. They grow along roadsides, fields, desert edges and grasslands. It grows best in sunny, humid or disturbed areas. Because riddles are slim in structure, wonderful in meaning, rich in content, diverse in forms and changeable, so guessing people should not only have extensive knowledge, but also have good habits of thinking, reasoning and judgment, and master some basic guessing methods in order to solve puzzles quickly, entertain their bodies and minds and enlighten their wisdom.