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

In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in （）.

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

Engine protection by means of an alarm or shutdown control can be obtained with devices that are sensitive 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?（）