Across
- 1. Replaceable by natural means in a short period of time
- 4. Any natural process that happens to Earth’s surface, such as weathering, erosion, or plate tectonics
- 7. The sum of all living matter on Earth
- 8. Resource A source or supply of energy that can be used to generate electric power to meet people’s needs
- 9. Resources that exist in the environment without human intervention
Down
- 2. Something that is 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
- 3. The layer of gas surrounding a planet that is held in place by gravity
- 5. Not replaceable by natural means within a short period of time
- 6. Water that collects in cracks and pores in underground soil and rock layers