In a bypass type lubrication system for a diesel engine, the dirty oil line to the centrifuge should be taken from the （）.

单项选择题Theoretical perfect combustion in a diesel engine yields by-products of （）.

A.aldehydes and carbon dioxide
B.water vapor and carbon monoxide
C.nitrogen and carbon monoxide
D.water vapor and carbon dioxide

单项选择题Which of the following devices is a common basic element with nearly all mechanical governors?（）

A.Power piston
B.Control rack
C.Weights acted on by centrifugal force
D.Isochronous droop spring

单项选择题A change in the degree of fuel atomization in a diesel engine would most greatly affect （）.

A.air turbulence
B.fuel penetration
C.fuel spray angle
D.fuel injection rate

单项选择题Scale and dirt accumulation in the waterside of a lube oil cooler will be indicated by a gradual increase in the lube oil（）.

A.TBN number
B.viscosity
C.temperature
D.foaming

单项选择题The lower section of a piston is called the （）.

A.land
B.skirt
C.crown
D.plate