Across
- 4. something that pollutes, esp. a waste substance that makes air, water, or land
- 6. a variety
- 8. an animal that hunts other animals for food
Down
- 1. to fill with more inhabitants than available resources can sustain
- 2. a way of hiding something by covering or coloring it
- 3. a natural process of evolution
- 5. to their environment survive and are able to reproduce, while those that are weak leave fewer or no offspring
- 7. or unhealthy; contaminant