（）diesel engines generally have two systems of lubrication:（）a total loss system feeding and a circulating system lubricating the running gear and cooling the pistons.

A.removing heat and deposits
B.neutralizing acidic products
C.lubricating
D.improving combustion efficiency

A.camshaft；fresh air
B.camshaft；starting air
C.electronic motor which is controlled by a computer；fresh air
D.electronic motor which is controlled by a computer；starting air

A.the starting air supply is cut off and fuel is injected into the cylinders
B.the fuel feeding is cut off and the turning gear is put in
C.the starting air supply is cut off and turning gear is taken out
D.the electric blower is shut down and fuel is injected into the cylinders