患者，女性，60岁，全牙列缺失，主诉原义齿咀嚼效率尚可，固位良好，但与本人原貌差别较大，要求重做全口义齿。口腔检查见、牙槽嵴吸收中等，颌位关系正常，下列与中性区的概念无关的是

A．未出现骨吸收之前的牙槽嵴顶区

B．自然牙列生长的区域

C．出现骨吸收后的牙槽嵴顶区

D．舌、唇、颊肌作用于义齿的力量相互平衡的区域

E．上前牙排在牙槽嵴顶的唇侧

开放作文。

     请根据下面提示，写一篇短文。词数不少于50。 

     In your spoken English class, your teacher shows you the following picture. You are asked to describe

the picture and explain how you understand it.

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