Question

synthetic materials
o have only negative effects on the environment
o are obtained directly from nature
o have undergone chemical reactions
o have no similarity to materials in nature

Explanation:

Synthetic materials are made through chemical reactions and have no direct - natural equivalent. They are not obtained directly from nature, and their properties can be different from natural materials. While they can have environmental impacts, it's not only negative.

Answer:

have no similarity to materials in nature