单项选择题
A.check hydraulic oil levels every hour
B.check the rams for overheating
C.check for excessive oil leakage from rams
D.drain water from telemotor cylinders each watch
单项选择题 The oil in a cargo winch gear box should be sampled periodically to （）.
单项选择题 A spur gear pump should be operated with the discharge valves （）.
单项选择题 The capacity of a centrifugal pump can be increased by the installation of a larger diameter impeller Another means of increasing the pump capacity is to （）.