英语听力文摘 English Digest 177、保护牙齿

　　Getting Rid Of Cavities
牙痛是继续忍受还是提前做好防护?爱护牙齿，每天的必修课。
M:Sorry,I'm late.I was brushing my teeth.
W:Brushing your teeth?Right before 'A Moment Of Science'? Why?
M:I'm trying to get rid of a cavity.
W:Get rid of a cavity?Are you stuck with a cavity once you have it?
M:It depends on how deep it is.Acid from bacteria in your mouth can cause your tooth to decay.First, the acid eats away the very hard outer layer of your tooth, called the enamel¹. Inside the enamel is the dentin. It’s spongy and has nerve endings, so your tooth might be sensitive to sweets or cold if the decay reaches there.But the cavity doesn’t really start to hurt until it gets through the dentin to the soft pulp². That’s when you get a toothache.

　　W:Oau！
M:Dentists will sometimes fix a cavity by putting in a filling while the decay is still in the enamel. But decay is reversible until it reaches the dentin. If it’s properly treated, the decay will stop, and the enamel will harden, although the tooth will never be perfect again.
W:So that's why you're brushing.Can you do anything else to help get rid of a cavity?
M:Dentists can also help by giving you a fluoride treatment, but you have to brush and floss regularly. You might have to give up soda³ and sweets.So it’s not easy–and dentists know that. That’s why they sometimes fill a cavity in its early stages, before it starts to hurt.
W:So you’re not stuck with tooth decay once it happens.?
M:No.But it’s better not to let it happen in the first place.

1 enamel   

n.珐琅，搪瓷，瓷釉；(牙齿的)珐琅质

参考例句：

• I chipped the enamel on my front tooth when I fell over.我跌倒时门牙的珐琅质碰碎了。
• He collected coloured enamel bowls from Yugoslavia.他藏有来自南斯拉夫的彩色搪瓷碗。

2 pulp   

n.果肉，纸浆；v.化成纸浆，除去...果肉，制成纸浆

参考例句：

• The pulp of this watermelon is too spongy.这西瓜瓤儿太肉了。
• The company manufactures pulp and paper products.这个公司制造纸浆和纸产品。

3 soda   

n.苏打水；汽水

参考例句：

• She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
• I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。