Explanation:
femur
The femur is one of the most researched bones in the human anatomy and forensic medicine. As the longest bone in the human body, it is well preserved in skeletal remains.
Answer:
The depth at which Drew found the algae
Explanation:
The dependent variable was the depth at which he found the algae, because that is what he measured on each day.
The independent variable was the sky conditions, since that changed from clear to cloudy, which impacted the dependent variable/the depth of the algae.
The answer is Model. Hope this helps!!
The answe is the 4th choice