Across
- 3. Water that collects in cracks and pores in underground soil and rock layers
- 5. Any natural process that happens to Earths surface, such as weathering, erosion, or plate tectonics
- 6. The sum of all living matter on Earth
Down
- 1. The layer of gas surrounding a planet that is held in place with gravity
- 2. a source or supply of energy that can be used to generate electric power to meet peoples needs
- 4. replaceable in natural means in a short period of time