Passage Two　　
14.
A) Coca Cola
B) Sausage
C) Milk
D) Fried chicken

15.
A) He has had thirteen decayed teeth
B) He doesn't have a single decayed tooth
C) He has fewer decayed teeth than other people of his age
D) He never had a single tooth pulled out before he was fifty.

16.
A) Brush your teeth right before you go to bed in the evening
B) Have as few of your teeth pulled out as possible
C) Have your teeth X-rayed at regular intervals
D) Clean your teeth shortly after eating.

答案及参考原文：

ABD

How many teeth have you had filled in the past two years? If you follow the advice of Dr. Forstic, you may be able to reduce the number of your visits to a dentist. Dr. Forstic conducted a two-year survey to find out how to prevent or reduce dental decay. 946 students took part in the experiment. 523 students cleaned their teeth within 10 minutes of eating. When possible, they used 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 clean after each meal group. At the end of the second year, the latter group had 53% fewer decayed teeth than the former group. Dr. Forstic has cleaned his teeth after every meal for 13 years and has not had a single decayed tooth(15). He pointed out that sugar is the major agent in dental decay, particularly, the sugar in sweets, cakes and soft drinks(14). Ideally you should keep a toothbrush in your pocket and use it immediately after you have finished eating(16). When this is impractical, you can at least make sure that you have a drink of water and let the water thought your teeth, to force out any particles of the food. 7 out of 10 people lose 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 the dentist is very pleasant. So, it is worthwhile making an effort to keep your own teeth as long as possible. The main preventive agent is simply water.

14. According to the passage, what type of food or drink is most likely to cause dental decay?
15. What does the passage tell us about the condition of Dr. Forstic's teeth?
16. What does Dr. Forstic suggest to prevent dental decay?