A. MISUNDERSTAND B. MISDIRECT C. MISCARRY D. MISBEHAVEREAD THE FOL...

33. A. misunderstand B. misdirect C. miscarry D. misbehaveRead the following passage and mark the letter A, B, C, or D on your answer sheet to indicate thecorrect answer to each of the questions.The cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removesminerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encouragesremineralization and neutralizes the acid. The rate at which bacteria in the mouth produce aciddepends on the amount of plaque on the teeth, the composition of the microbial flora, and whetherthe bacteria of the plaque have been "primed" by frequent exposure to sugar. To keep your teethhealthy, a regular dental hygiene program should be followed.Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria inthe mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible,enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking waterwhen teeth are forming, some fluoride is incorporated into the enamel of the teeth, making themmore resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting theremineralization of early carious lesions.In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduceyour intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals andnot between. The number of times you eat sweets rather than the total amount determines how muchharmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality ofyour saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brushand floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective.Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., thatscrape offplaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followedwhen eating sweets.