乳磨牙根尖周病变瘘管最常出现的位置是
A．颊侧根尖区黏膜
B．颊侧根分歧处黏膜
C．舌侧根尖区
D．舌侧牙颈部
E．根侧黏膜
参考答案：B
The teacher asked the girl again, raising his voice a bit, but still_______no answer.
A．receiving
B．received
C．receive
D．to receive
简述喷吹罐下部安装流化装置的作用？
