Across
- 2. / inner tissue of a leaf
- 3. / main atmospheric organic trace gas
- 4. dioxide / gas that needs to be reduced
- 5. / lower atmosphere layer
- 7. fuels / made from decomposing plants and animals
- 8. oxygen species / highly reactive chemicals
- 9. / timing of phases occurrence in the life cycle
Down
- 1. / state of balance among systems
- 2. / found in cytoplasm
- 6. / second layer of earth's atmosphere