单项选择题
A.向轴瓦加油盘动转子B.往联轴器上及轴颈上加水冷却C.加以保温防止联轴器变形D.在室温下缓慢冷却
A.100mmB.150mmC.200mmD.250mm
A.上升B.下降C.不变D.先升后降