单项选择题
Which is not the maintenance work for shaft bearings in transmission system?（）
A.check oil level in bearing sump B.check them for leakagec through end seals C.pump bilges in time D.check temperature
单项选择题 Water lubricated tailshaft bearings wear,（）
单项选择题 When sailing in cold zones, the（） should be drained of water.
单项选择题 When sailing in cold zones, the（） should be heated.
