金瓷冠的金属基底冠有瓷覆盖部位的厚度一般为()
A.0.5mm
B.0.6mm
C.0.7mm
D.0.8mm
E.1mm
参考答案:A
( )party shall notify the other party of the ratification by their respective authorities.
A.Each B.One C.Either D.A
简述环境毒理学的基础。