听力原文：How many teeth have you had filled in the past two years？ If you follow the advic

听力原文： How many teeth have you had filled in the past two years？ If you follow the advice of Dr. Faustick 'you may be able to reduce the number of your visits to a dentist. Dr. Faustick conducted a twoyear survey to find out how to prevent or reduce dental decay. 946 students took part in an experiment. 523 students cleaned their teeth within ten minutes of eating when possible they used a tooth brush, when this was impossible they washed their mouth thoroughly with water. The remaining 423 students merely cleaned their teeth when they went to bed and when they got up in the morning. All the students had their teeth X rayed at the end of the first and second years. At the end of the first year, the night and morning group had three times as many decayed teeth as the dean after each meal group. At the end of the second year the latter group had 53 percent fewer decayed teeth than the former group. Dr. Fausstick has cleaned his teeth after meal for thirteen years and has not had a single decayed tooth. He pointed out that sugar is a major agent in dental decay. Particularly the sugar in sweets, cakes, and soft drinks. Ideally you should keep a tooth brush in your pocket and use it immediately after you have finished eating. When this is impractical you can at least make sure that you have a drink of water and let the water through your teeth to force out any particles of food. 7 of out 10 people loose at least half of their teeth by the time they are fifty. Many have a complete set of false teeth by that time. In any case neither toothache nor a visit to a dentist is very pleas ant. So it is worthwhile making an effort to keep you own teeth as long as possible. The main preventative agent is simply water.

(23)

A．Coca Cola.

B．Sausage.

C．Milk.

D．Fried chicken.