Question

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 (齒齦)．

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.

1.According to the passage，which of the following statements is NOT true?

A．Just older and wiser people can have wisdom teeth.

B．Wisdom teeth can cause problems if not in their right place.

C．Impacted wisdom teeth can’t grow out of the gum fully.

D．Wisdom teeth that only partly break can get bacterial infections.

2.Wisdom teeth should be removed________.

A．when they break through the gums

B．when they are below the gums

C．if they are not well lined or get impacted

D．if they take up enough room in the mouth

3.We can learn from the passage that________.

A．impacted wisdom teeth have the risk of getting infected

B．ancient humans need chewing teeth because of their happy life

C．older adults are the best candidates for wisdom teeth removal

D．more chewing teeth are needed for the diet of modern humans

4.The main purpose of the passage is to________.

A．advise B．persuade C．comment D．introduce

 

Answer 1

1.A

2.C

3.A

4.D

【解析】

1.細節(jié)理解題。根據文章第一段可知，所謂的智齒是指在青少年晚期或二十歲出頭長出的牙齒，而不是只有老人或智者才有的牙齒。

2.細節(jié)理解題。根據文章第四段第一句“Wisdom teeth that are not well lined and become impacted are often removed.”可知，C項正確。

3.推理判斷題。根據文章第三段可知，阻生智齒(即impacted wisdom teeth)會在牙齒周圍給細菌留出進入的空間，這就有被感染的風除。故選A。根據第四段最后一句可排除C項；根據最后一段可排除B、D兩項。

4.寫作意圖題。本文是一篇說明文。文章主要介紹了長智齒的大約時間、智齒可能導致的問題、拔掉智齒的時間、為什么長智齒等內容。所以本文寫作的主要目的就是介紹。