6. 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

The non-living things which were once a part of living things are butter, leather, wool, cooking oil, apple, and rubber. The sources of these non- living things are given below:

(a) Butter is made by churning milk, which is obtained from dairy animals.

(b) Leather is obtained from animal skin.

(c) Wool is a fabric made from the hair of sheep.

(d) Cooking oil is obtained from the seeds of the some plants.

(e) Apple is a fruit obtained from apple tree.

(f) Rubber is obtained from the latex of rubber tree.

Soil, electric bulb, and salt are non-living things which were never a part of any living thing.