2016高考英语二轮阅读理解一百六十集选练（35）

　　阅读理解Wisdom teeth are normally the last teeth to appear.This usually happens when people are in their late teen years or early twenties，in other words，when they are older and wiser.

　　Wisdom teeth can grow into place normally and never cause a problem.But often there is not enough room for them in the mouth；they might crowd other teeth.Sometimes they even push sideways through the gums (齿龈)．

　　An impacted wisdom tooth is one that fails to completely rise through the gums.Wisdom teeth that only partly break through can leave space for bacteria to enter around the teeth.Infection (感染) is a risk in these cases.

　　Wisdom teeth that are not well lined and become impacted are often removed.The American Dental Association says removal is generally advised when wisdom teeth only partly break through the gums.Removal is also advised if there is a chance that wisdom teeth ate poorly lined.The best time to remove is before the teeth cause any problems or pain.Young adults are the best candidates for wisdom teeth removal.

　　But why do we have wisdom teeth if we often need to get them removed？One theory has to do with our diets.Scientists say the diet of ancient humans probably required more chewing teeth.Life was probably a little rougher on the teeth back then，too.So it was good to have extras.

【2016届高考英语二轮复习阅读理解一百四十集选练：（35）】相关文章：

★ 2017高考四川省广安市英语阅读理解一轮系列训练：17（含解析）

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (73)

★ 2017届高考英语二轮复习课时训练：5（含解析）

★ 2017高考四川省广安市英语阅读理解一轮系列训练：16（含解析）

★ 2016届高考英语二轮复习阅读理解一百四十集选练：（61）

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (31)

★ 2017高考四川省广安市英语阅读理解一轮系列训练：27（含解析）

★ 重庆市2014高考英语阅读理解一轮（精品）训练题（17）附答案

★ 【北京专用】2014届高考英语一轮复习方案课时作业：必修5 Unit 1 Great scientists

★ 【人教版】2014届高考英语一轮复习指导考点针对练：选修6 unit5《The power of nature》