Which of the non-living things listed below, were once part of a living thing? Butter, Leather, Soil, Wool, Electric bulb, Cooking oil, Salt, Apple, Rubber

Among the listed items, leather, wool, cooking oil, apple, and rubber were once part of living things. Leather comes from animal skin, wool from sheep’s fleece, cooking oil from plants or animals, apples from trees, and rubber from the sap of rubber trees. The remaining items like butter, soil, electric bulbs, and salt were not directly part of living organisms.