The medication would be the controlled variable, the factor that remains constant.
Answer:
The presence of small amounts of heat-trapping greenhouse gases in the atmosphere warms Earth's surface, resulting in a planet that sustains liquid water and life. c. Changes in climate conditions can affect the health and function of ecosystems and the survival of entire species.Earth and its atmosphere are continuously altered. Plate tectonics shift the continents, raise mountains and move the ocean floor while processes not fully understood alter the climate. Such constant change has characterized Earth since its beginning some 4.5 billion years ago.
Explanation:
The third level, secondary consumers.
