1.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 are chewing teeth， at the back of the mouth. The third set of chewing teeth， if you have them， are your wisdom teeth.
　　They can grow into place normally and never cause a problem. But often there is not enough room for them in the mouth. 2. 他們可能会挤别的牙齿。Sometimes they even push sideways through the gums （牙龈）.
　　People should have the placement of their wisdom teeth examined between the ages of sixteen and twenty. X-rays can show wisdom teeth that are below the gums.
　　The American Dental Association says removal （除去） is generally advised when wisdom teeth only partly break through the gums. Removal is also advised if 3. there is a chance that poorly placed wisdom teeth will damage other teeth. And removal is called for in cases where fluid （流体） collects around a wisdom tooth that is partly or fully below the gum.
　　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 harder on the teeth back then， too. 4. 所以多几颗牙齿有好处。
　　The removal of wisdom teeth is performed by doctors. They say if removal is advised， the best time to do it is before the teeth cause any problems or pain.
　　Patients can have general anesthesia （麻醉） during the operation. Or they might choose to have a local painkiller and remain awake. 5. It may depend on the number of the wisdom teeth to be removed.
　　句子翻译：
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　　答案：
　　1.智齿通常是最后长出的牙齿。
　　2.They might crowd other teeth.
　　3.长得不好的智齿会损害到别的牙齿。
　　4.So it was good to have more.
　　5.这得取决于移去的智齿的数量。