River pebble hole-taking as the main figure

Quick answer：

River pebbles, also known as cobblestones, are rounded or irregularly shaped stones found in riverbeds. They are commonly used in construction and landscaping due to their durability and aesthetic appeal. The phrase 'river pebble hole-taking as the main figure' might refer to a design element where river pebbles are used to create a focal point or pattern in a design, possibly in a landscape or architectural context.