Answer:
It's important for a scientist to try to hold all variables constant except for the independent variable. If a control variable changes during an experiment, it may invalidate the correlation between the dependent and independent variable. When possible, control variables should be identified, measured, and recorded.
Standard precautions
N-95 tuberculosis standard
Blood-borne pathogen standard
Resource Conservation and Recovery Act - requires labeling, storage, transportation, and disposal of biological waste according to fedral standards. .-.
It takes 27 days for the moon to orbit the earth
Answer: B, the number of species in a community
Explanation:
1: They support each other
2: They effect the earth.