固定矫治器治疗中的牙釉质脱矿发病率达()
A.10%
B.20%
C.30%
D.50%
E.90%
参考答案:D
If it had been fine yesterday, we could have watched that air show. But it _____________ all day.
A.has rained
B.had rained
C.rained
D.rains
唐高宗至唐德宗铜镜类型及艺术风格(650~804)。