Across
- 5. another type of nonrenewable energy that is NOT a fossil fuel
- 6. a liquid fossil fuel found in underground rock formations
Down
- 1. ______ mining is used when coal is located near the top of Earth.
- 2. types of resources that cannot be created or take a long time to regenerate
- 3. a fossil fuel found underground mostly made of methane
- 4. _____ mining is used when coal is located deep below Earth's surface