Across
- 3. energy from natural sources
- 4. environmental indicator
- 7. is a mixture of organic substances
- 9. is the disappearance of all members of a species
- 10. convert waste into new products
Down
- 1. environmental indicator
- 2. biomass produced in past ages
- 5. variation in the state of the climate system
- 6. caused by overflowing rivers, torrential rains, hurricanes and tidal waves
- 8. is the simplest alkane hydrocarbon
- 11. natural environment encompasses all living and non-living