A diesel engine piston ring face is in direct contact with the （）.

White smoke exhausting from an operating diesel engine may indicate （）.

If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a （）.

Lube oil cannot be efficiently filtered if its （）.

Routine monitoring of a diesel engine should include （）.

The main purpose of the piston oil scraper rings is to （）.

When would the available energy of the exhaust gases of a two-stroke/cycle diesel engine be insufficient to drive an exhaust gas turbocharger, resulting in the incorrect amount of air for combustion?（）

To determine if the lube oil filter elements need changing, （）.

If the main engine of an unattended engine room shuts down automatically, it will be indicated by an alarm （）.

What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）