Which of these is the best example of the sustainable use of a natural resource?

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

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?

Were you able to observe the nucleolus in any of the cells if so which ones