孔φ20+0.015 +0与轴φ20-0.010 -0.015配合,最小间隙是()。
A.0.015
B.0.010
C.0.030
D.0.025
参考答案:A
Unfortunately, when I arrived, Mary , so we only had time for a few words.
A.was just leaving
B.just left
C.has just left
D.had just left
下述金属砷的性质,不正确的是()
A.遇牙髓氧化成亚砷酸
B.作用较亚砷酸缓和
C.不会造成牙龈和牙槽骨的坏死
D.封药时间5~7天
E.可用于乳牙的牙髓失活