滚筒、托辊要保持正常（），磨损及坏了的要在停机时修理更换。
参考答案：运转
色灯进站信号机红灯灭灯后仍可以开放允许信号。
Project selection methods involve measuring value or attractiveness to the project owneror sponsor and may include other organizational decision criteri
A．______ is not a project selectionmethod．A．Benefit contributionB．Exp
