Across
- 2. the layer of gas surrounding of a gas surrounding a planet that is held in place by gravi
- 7. Resources that exist in the environment without human interaction
- 8. Replaceable by natural in a short period of time
- 9. A source of a supply or energy
Down
- 1. Not replaceable by natural means within a short period of time
- 3. The sum of all living matter on Earth
- 4. Something that us needed by organisms and is not infinite in its abundance in the environment if it is exhausted then the organisms that need it cannot survive
- 5. Water that collects in cracks and pores in underground soil and rock layers
- 6. Any natural process that happens to Earths surface, such as weathering erosion or plate tectonics