centres — Geometry. the middle point, as the point within a circle or sphere equally distant from all points of the circumference or surface, or the point within a regular polygon equally distant from the vertices.
stocks — a supply of goods kept on hand for sale to customers by a merchant, distributor, manufacturer, etc.; inventory.
sources — any thing or place from which something comes, arises, or is obtained; origin: Which foods are sources of calcium?
supplies — to furnish or provide (a person, establishment, place, etc.) with what is lacking or requisite: to supply someone clothing; to supply a community with electricity.
