问题
单项选择题
缩余釉上皮
A．在成釉器内、外釉上皮之间的星形细胞
B．钟状期末牙板断裂后残留的上皮岛
C．釉质发育完成后，其表面由成釉器各层细胞相互结合形成的鳞状上皮
D．釉质发育完成后，成釉细胞在釉质表面分泌的无结构有机物薄膜
E．上皮根鞘断裂后遗留在牙周膜中的上皮岛
答案
参考答案：C
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缩余釉上皮
A．在成釉器内、外釉上皮之间的星形细胞
B．钟状期末牙板断裂后残留的上皮岛
C．釉质发育完成后，其表面由成釉器各层细胞相互结合形成的鳞状上皮
D．釉质发育完成后，成釉细胞在釉质表面分泌的无结构有机物薄膜
E．上皮根鞘断裂后遗留在牙周膜中的上皮岛
参考答案：C
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| What do you do on weekends? Some people like to 1 at home, but others like to go 2 a walk or play football. My friend Jack works hard in a factory during the 3 . On weekends, he always 4 the samething. On Saturday he 5 his car and on 6 he goes with his family to the village by car. His uncle and aunt have a farm there. It isn't a 7 one, but there are always 8 things to do on the farm. The children help them with the animals and give them their 9 . Jack and his wife help in the fields(田地). At the end of the day, they are all 10 and Jack's aunt gives them a big meal. | ||||
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