玻晶砖是一种新型环保材料,它的制作步骤排序正确的是()。
A.粉碎→成型→退火→晶化
B.粉碎→晶化→成型→退火
C.粉碎→成型→晶化→退火
D.粉碎→晶化→退火→成型
参考答案:C
—Hello, may I speak to Mr Green, please?
—Sorry. He a meeting. Can you call him later?
A.has
B.is having
C.will have
D.had
油品靠近管壁处的流动形式是()
A.湍流
B.浊流
C.滞流
D.层流