D. Avoid being with others who smoke
Hope this helps :)
1. True- because scientific theory means that <span>idea supported through research that attempts to explain existing observations or predict new ones.</span>2. False- because a cross-sectional means that its a study that is about different groups.
3. B-<span>An extraneous variable clarifies the relationship between the independent and dependent variables.</span>
Yes people can get HIV without having full blown aids
