【单选题】一般来说,成本中心的变动成本大多是可控成本,而固定成本大多是不可控成本。( )
【单选题】工程上,常以()流体为基准,计量流体的位能、动能和静压能,分别称为位压头、动压头和静压头
【单选题】What's the difference between a reference and a bibliography?
A.
A reference is always shorter than a bibliography.
B.
A reference lists the author's favorite readings.
C.
A bibliography usually contains broader contents than a reference.
【单选题】工程上常以( )流体为基准,计量流体的位能、动能、静压能分别称为位压头、 动压头和静压头。
【单选题】下列不属于焊条药皮的作用是( )
D.
保证焊缝金属获得具有合乎要求的化学成分和机械性能
【单选题】What’s the difference between a reference and a bibliography?
A.
A reference is always shorter than a bibliography.
B.
A reference lists the author ’ s favorite readings.
C.
A bibliography usually contains broader contents than a reference.