Across
- 3. chemical element with the symbol C, which forms the basis of all known life.
- 6. large body of salt water that covers most of the Earth.
- 7. layers of gases surrounding a planet or other celestial body.
- 9. living or once-living thing.
- 10. breathing.
Down
- 1. process by which plants turn water, sunlight, and carbon dioxide into water, oxygen, and simple sugars.
- 2. cycle series of processes in which carbon (C) atoms circulate through Earth's land, ocean, atmosphere, and interior.
- 4. remnant, impression, or trace of an ancient organism.
- 5. large, concentrated supply or reserve.
- 8. having to do with the ocean.