局部因素造成牙齿内源性牙齿变色的原因有()。
A.牙髓出血
B.牙髓组织分解
C.牙本质脱水
D.充填材料及药物
E.食物
参考答案:A, B, C, D, E
I’m calling about the apartment you __the other day. Could you tell me more about it?
A.advertised
B.had advertised
C.are advertising
D.will advertise
哪一样原料不属于化学膨大剂()
A.发粉
B.酵母
C.小苏打
D.阿摩尼亚