患者，男，61岁，戴全口义齿l周，上唇牵动时感觉疼痛，左侧咬食物时义齿不脱位，右侧咬食物时义齿脱落，有时将颊部软组织咬出血肿，检查见正中咬合接触良好，上唇系带处2mm大小的溃疡，左侧第二磨牙区的颊黏膜见4mm直径大小的血肿。
引起左侧颊部咬出血肿的可能原因，下列哪项除外
A．颊部软组织内陷
B．后牙覆盖较小
C．后牙排列偏颊侧
D．后牙覆盖较大
E．咬合面有尖锐边缘
参考答案：D
解析： 由于后牙缺失时间过久未修复，常导致两侧颊部内陷。可通过加大后牙覆盖、增厚上颌后牙颊侧基托以推开内陷的颊黏膜加以改善。答案除D外均是义齿后牙咬颊的原因。
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| Anna lived on the side of a valley. One summer, there was a very big 1 , and a lot of houses down below Anna's were washed away. Anna's house was 2 enough to escape the flood, so when the water had 3 and the other houses were standing there 4 no roof and no walls and all covered with mud(泥), her house was just all right. Her house was quite small, her husband was dead, and she had four children, 5 Anna took in one of the families that had lost 6 in the flood and she 7 her home with them until it was 8 for them to rebuild their house. Anna's friends were 9 when they saw Anna do this. They could not understand why Anna wanted to give 10 so much more work and trouble when she already had quite a few children to 11 . "Well," Anna 12 her friends, "at the end of the First World War, a woman in the town where I then lived found herself very 13 , because her husband had been killed in the 14 and she had a lot of children, 15 I have now. The day before Christmas, this woman said to her children, 'We won't be able to have much for 16 this year, so I'm going to make only one present to all of us. Now I'll go and get it.' She came back with a 17 who was even poorer than they, and who had no parents. 'Here's our 18 ,' she said to her children. The children were 19 and happy to get such a present. They 20 the little girl, and she grew up as their sister. Such was that Christmas present." | ||||
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