Sulfur bacteria function as the main producers in what type of environment? A. Tropical rain forest
B. High desert
C. Deep ocean

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system

9. the history of life on earth is recorded in

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of