题目
Humans have wisdom teeth probably because (). A. our ancestors needed to chew more when they grew up B. our ancestors’ teeth grew at late teens or early twenties C. our ancestors ate foods without cooking D. our ancestors had very tough livesA.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.B.Wisdom teeth are chewing teeth, at the back of the mouth. They 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(牙床).C.An impacted wisdom tooth is one that fails to completely rise through the gum-the term is erupt. Wisdom teeth that only partially erupt can leave space for bacteria to enter around the tooth. Infection is a risk in these cases.D.Wisdom teeth’that are not well in place and become impacted are often removed. 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.E.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 poorly placed wisdom teeth will damage other teeth. And removal is called for in cases where fluid collects around a wisdom tooth that is partly or fully below the gum.F.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 prehistoric 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.G.The American Association of Oral and Maxillofacial (上颌面的) Surgeons says young adults are the best candidates for wisdom teeth removal. The group says older patients may be at greater risk for disease in the tissue surrounding the teeth.H.After surgery, there can be swelling of the gums and face and some pain. Both can be treated with cold wraps and medication(药物治疗).
Humans have wisdom teeth probably because (). A. our ancestors needed to chew more when they grew up B. our ancestors’ teeth grew at late teens or early twenties C. our ancestors ate foods without cooking D. our ancestors had very tough livesA.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.B.Wisdom teeth are chewing teeth, at the back of the mouth. They 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(牙床).C.An impacted wisdom tooth is one that fails to completely rise through the gum-the term is erupt. Wisdom teeth that only partially erupt can leave space for bacteria to enter around the tooth. Infection is a risk in these cases.D.Wisdom teeth’that are not well in place and become impacted are often removed. 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.E.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 poorly placed wisdom teeth will damage other teeth. And removal is called for in cases where fluid collects around a wisdom tooth that is partly or fully below the gum.F.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 prehistoric 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.G.The American Association of Oral and Maxillofacial (上颌面的) Surgeons says young adults are the best candidates for wisdom teeth removal. The group says older patients may be at greater risk for disease in the tissue surrounding the teeth.H.After surgery, there can be swelling of the gums and face and some pain. Both can be treated with cold wraps and medication(药物治疗).
题目解答
答案
A
解析
本题考查对文章内容的理解，需要根据段落信息推断人类拥有智齿的进化原因。关键点在于抓住段落F中的核心理论：史前人类的饮食需求。文章指出，由于食物需要更多咀嚼，智齿作为额外牙齿在当时具有适应性意义。选项需与这一理论对应。
选项分析
- 选项A：祖先需要更多咀嚼能力。段落F明确提到“史前人类的饮食可能需要更多咀嚼牙齿”，直接支持此选项。
- 选项C：祖先吃未经烹饪食物。段落未提及烹饪方式与智齿的直接关系，仅强调咀嚼需求，故排除。
结论
段落F的理论直接对应选项A，说明智齿的存在与祖先的咀嚼需求相关。