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当前学科:口腔执业医师
题目:
单选题
使用超声波洗牙机时。工作头应与牙面成()
A
与牙面平行或小于20°角
B
与牙面平行或小于15°角
C
25°角左右
D
与牙面平行或小于30°角
E
80°角左右
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