水磨石的质量等级可分为（）。
A.优等品、合格品
B.优等品、一等品、合格品
C.特级品、一级品、合格品
D.一等品、合格品
参考答案：B
that it has been No．1 hit on the pop charts over the past month·
A．Simon’s newly released album is very well—received
B．SO well received Simon’s newly released album is
C．Well．received is Simon’s newly released album
D．So well received is Simon’s newly released album
手术用金属器械宜采用
A．高压蒸汽灭菌法B．干烤C．滤过除菌D．紫外线E．煮沸消毒
