单项选择题
A.to retain B.to remain C.to maintenance D.to have
Constant cooling the various components of diesel engin...
单项选择题Constant cooling the various components of diesel engine has a number of functions except for （）.
A.good lubrication B.low thermal stress C.good mechanical properties D.acid corrosion
Compressed air is used on board ship （）.A.for starting ...
单项选择题Compressed air is used on board ship （）.
A.for starting diesel engines B.in pneumatic control system C.in pneumatic tools D.All the above are true
Compressed air is supplied by air compression to （）.A.t...
单项选择题Compressed air is supplied by air compression to （）.
A.the air receivers B.the starting valves C.the cylinder covers D.the distributors
