【例2】

　　【預覽選項】

　　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.

　　【聽前預測】

　　14.由15、16題各選項內容可推測本文主題應該是關于牙齒保健。而本題選項都是食物或飲料，結合對文章主題的分析，本題很可能是問哪種東西對牙齒有害。根據常識，四種食物或飲料中Coca Cola最容易傷害牙齒，因為其含糖量較高。

　　15.選項表明本題考查的是某人的牙齒狀況(是否有蛀牙)。[A]、[B]、[C]都是關于蛀牙的問題，[D]則是關于拔牙的問題，故可初步排除。

　　16.選項表明本題考查的是保護牙齒的正確方法。根據對前兩題的分析可推知，本題很可能是關于預防蛀牙的方法，并且很可能與飲食有關。因此[B]、[C]為答案的可能性較小;而[A]、[D]為答案的可能性較大。

　　【聽音驗證】

　　How many teeth have you had filled in the past 2 years? If you follow the advice of Dr. Forstic, you may be able to reduce the number of your visit 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 toothbrush. 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. [15B] Dr. Forstic has cleaned his teeth after every meal for 13 years, and has not had a single decayed tooth. [14A]He pointed out that sugar is a major agent in dental decay, particularly the sugar in sweets, cakes and soft drinks. Ideally, [16D]you should keep a toothbrush 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. Seven out of ten people lose at least half 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 pleasant. So, it is worthwhile making an effort to keep your own teeth as long as possible. The main preventive agent is simply water.

　　【答案解析】

　　14. According to the passage, what type of food or drink is most likely to cause dental decay?

　　【解析】 選[A]。細節(jié)題。根據原文中“ sugar is a major agent in dental decay, particularly the sugar in sweets, cakes and soft drinks.”而 Coca Cola 是soft drinks中的一種，故答案為[A]。

　　15. What does the passage tell us about the condition of Doctor Forstic’s teeth?

　　【解析】 選[B]。細節(jié)題。根據原文中Dr. Forstic has cleaned his teeth after every meal for 13 years, and has not had a single decayed tooth.可知Dr. Forstic沒有一顆蛀牙，故答案為[B]。

　　16. What does Doctor Forstic suggest to prevent dental decay?

　　【解析】 選[D]。細節(jié)題。根據原文中you should keep a toothbrush in your pocket and use it immediately after you have finished eating.可知飯后保持牙齒的清潔是防止蛀牙的有效方法，故答案為[D]。