CRH5A动车组塞拉门“开启” 和“关闭” 的直接行使机构是( )?
Measurement is the comparison of the unknown quantity with (). 译:测量是将未知量与什么进行比较的过程?
A. known quantity
B. a ruler
C. a scale
D. a unit
Which is NOT the objectives of metrology? 译:下列哪项不是技术测量的对象?
A. length
B. voltage
C. art
D. brightness
What’s the purpose of metrology?. 译:技术测量的目的是什么?
A. describing things
B. making things
C. quality control
D. all of the options(全部选项均正确)