【单选题】Redhat公司发布的Linux版本中,若要使得用户登录验证,需要修改以下( )脚本。
【单选题】在Redhat公司发布的Linux版本中,若要使得用户登录验证,需要修改以下______脚本。
【单选题】Lubricating oil systems for diesel engine journal bearings are usually lubricated by which of the following types of lubricating oil systems?
【单选题】In engines with system, the lubricating oil can be added to the engine through the filling hole in the crankcase cover, by using a hand oil can, or through the separator pipe
【单选题】For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an _____.
D.
drilled passage through the camshaft
【单选题】Engine coolant accumulating in the diesel engine lubricating oil can result from a _______.
D.
cracked cylinder head or liner
【单选题】Lubricating oil for an engine is stored at the bottom of the _____, known as the sump or in a drain tank located beneath the engine.
【单选题】Excessive lubricating oil consumption in a running diesel engine can be caused by ________.
A.
clogged lube oil piping
B.
excessive valve-guide clearance
C.
high lube oil viscosity
D.
low lube oil temperature
【简答题】What's the function of the lubricating oil in main engine?
【单选题】In a normally operating diesel engine, the main cause of lubricating oil contamination in the crankcase is a result of the _____.
A.
metal particles loosened by wear
B.
air when no air cleaners are used
C.
condensation of water vapors
D.
breakdown of the lubricating oil by dilution