磨煤机油系统正常运行维护项目有哪些?
参考答案:
油滤网差压高切换清理,维持正常油位,调整油温/油压,投入电加热和冷却水。
_____ makes his parents proud is _____ his son has been admitted by Beijing University.
A.That; because
B.That; what
C.What; that
D.What; because
内径千分尺可测量最小孔径为()。
A.5mm
B.50mm
C.75mm
D.100mm