Maintaining the close tolerances in diesel fuel pumps and injectors requires the use of（）.

A.it gets dark in color
B.a sample rubbed between fingers feels thin
C.it has been in use for a specified interval
D.it no longer supports combustion

A.decrease your engine speed
B.ignore it
C.increase your engine speed
D.stop your engine until the rough weather passes

A.discharge a CO₂ extinguisher in the air inlet
B.pull off the distributor cap
C.secure the jacket water
D.secure the starting air supply valve