d. They completely mix with one another.
13. Which of the following changes is useful to the environment?
2. Making recycling projects
b. Cutting down trees.
Burning old tires.
d. Throwing garbage into bodies of water.
14. The following changes in the materials are useful to the environment except one.
a. Using old newspapers in wrapping gifts
b. Using eco bag when buying groceries.
c. Using detergents in washing clothes in the river.
d. Using both sides of bond paper when writing
15. Which of the following changes in the materials is useful to the environment?
a. Recycling old clothes.
b. Shaping pieces of wood into chairs.
c. Making flower pots from old tires.
d. All of the above​