A dental student wants to test if fluoride is an effective a…
A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevents tooth decay. What would be an effective control group to ask this question?
Read DetailsIndividuals that are heavy smokers may eventually have troub…
Individuals that are heavy smokers may eventually have trouble clearing the mucous from their lungs because the structures that move fluid along the epithelial lining of the lung become damaged over time. What are these structures called?
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