单项选择题
A.0.95~0.97B.0.93~0.97C.0.9~0.97D.0.92~0.95
A.定期维修B.视情维修C.事后维修D.应急维修
A.早期故障期B.偶然故障期C.耗损故障期D.潜在故障期