单项选择题
A.疼痛 B.牙体磨损 C.修复体松动 D.龈缘炎 E.牙髓炎
A.0.25% B.0.50% C.1% D.2% E.2.50%
A.0.50% B.1% C.1.50% D.2% E.2.50%