Question

find the relative clause. if it is nonrestrictive, set it off with commas. if it is restrictive, submit the text without making any changes. when adding organic materials to a compost pile, gardeners should avoid animal products and fats in favor of scraps from plants that have not been treated with pesticides.

Explanation:

A relative clause starts with a relative pronoun like "that", "which", "who", etc. Here, "that have not been treated with pesticides" is a relative clause modifying "scraps from plants". It is restrictive as it is essential to identify which plant - scraps are preferred. Removing it would change the meaning of the sentence.

Answer:

When adding organic materials to a compost pile, gardeners should avoid animal products and fats in favor of scraps from plants that have not been treated with pesticides.