I think true if its not sorry
Answer: They usually run tests too see. For example, that's why they made blood tests. They take you blood from you, and run tests to see if you have a disease.
Explanation: Hope it helps!
Answer:
Control group
Explanation:
A control group is<em> a group of individuals in an experiment where the independent variable being tested (the exposition to cigarette smoke in this case) can't influence the results.</em> This control group will be then compared to the experimental group (exposed to the smoke) to see the effect of the variable evaluated.
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