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8. Dental caries is another name for tooth decay where bacterial
infection affects the hard outer layer of the teeth.
9. Periodontal disease is a bacterial infection that destroys the
supporting structures holding the teeth in their place.
10. Tobacco reduces blood flow to the gums therefore, the gums are
deprived of proper oxygen supply and nutrients needed to stay
healthy and prevent bacterial infections.
Task 6. Retell the text.