Across
- 2. To contaminate
- 5. A concept or idea to test
- 6. Layer of gases surrounding Earth
- 8. The weather conditions prevailing in an area in general or over a long period
- 9. About the relation of living organisms to one another and to their physical surroundings
- 10. Earth's solid part
Down
- 1. Prevention of wasteful use of a resource
- 3. All water forms
- 4. The period in which manufacturing was done with machines
- 7. All living things