Complete neutral source
Complete original fictional tree-pot viewing account. A sealed display sketch P shows brown particles, two leaf pieces and spaces. Its picture window shows no visible animal; organism identity/count, nutrients, water movement and plant growth are not measured. F3 describes soil roles in supporting plants, providing habitat and regulating water. That general account is not a result from this display or proof that a particular pot cleans drinking water. The visitor’s job is to understand two useful soil roles and a view-level limit. A possible later observation plan would keep the sealed display closed, use the same view/window and record visible features; no observation has yet been conducted by the child.