The piston crown employs the usual jet-shaker principle with an arrangement of cooling bores in the crown so that the surface temperatures of the crown are moderate with a very even distribution（）
A、water cooling
B、oil cooling
C、air cooling
D、combined cooling
The bore of a diesel engine cylinder describes the （）
A、swept volume of the cylinder
B、inside diameter of the cylinder
C、piston displacement in the cylinder
D、length of the piston stroke
When start a screw pump, the by pass valve should be （）.
A、closed
B、opened fully
C、cracked open
D、partly open
Moisture in a D-Cmotor would cause （）.
A、short circuit
B、speed up
C、slow down
D、hunting
If the PSCO has clear grounds for carrying out a more detailed inspection,（）
A、the master should be immediately informed
B、the master will be prohibited from contacting the Administration or other organization
C、he will carry out the inspection after the master be informed and be ready
D、he will carry out the inspection without informing the master
Any carbon built up on surfaces must be washed away by （） additives and held in suspension by a （） additive.
A、dispersant；detergent
B、detergent；dispersant
C、dispersant；dispersant
D、detergent；detergent
