Across
- 1. plants and animals How did some of the animals get nitrogen?
- 3. What form is commonly used with plants?
- 5. into water vapor?
- 6. five percent how much of the earth is water?
- 10. seven percent how much of the earth is saltwater?
- 11. Carbon deposits into the ocean floor when the animal what?
Down
- 1. dioxide Green house gases and what will make the world frozen without it?
- 2. What do plants need to grow?
- 3. Can nitrogen be used as a nutrient by plants and animals?
- 4. percent how much of the earth is freshwater?
- 7. what do you call the process in which water
- 8. five percent how much is land?
- 9. Is the growth place for plant limited or unlimited?