关于正畸疼痛的影响因素,下列哪一项是不正确的()
A.年龄
B.个体差异
C.矫治力的大小
D.牙周膜受压缺血、出现炎症反应
E.急性根尖炎
参考答案:E
Only after they had discussed the matter for several hours ________ a decision.
A.they reached
B.did they reach
C.they reach
D.do they reach
使用机械强度高的合成催化剂,可减少催化剂的粉化。