机组打闸后转速降至1000r/min,应启动(),以防止汽轮机油膜破坏造成轴瓦的损坏 发布时间:2019-01-30 12:21 │ 来源:www.tikuol.com 题型:单项选择题 问题: 机组打闸后转速降至1000r/min,应启动(),以防止汽轮机油膜破坏造成轴瓦的损坏。A.顶轴油泵B.润滑油泵C.调速油泵D.抗燃油泵
题型:单项选择题 E-mail, as well as telephone,______ an important part in daily communication.A.is playingB.have playedC.are playingD.hoped 查看答案