An advantage of aluminum pistons, when compared to cast iron pistons is （）.

单项选择题Which of the combustion parameters listed is used in a diesel engine, but NOT related to the injection system?（）

A.Atomization
B.Metering
C.Effective stroke
D.Penetration

单项选择题Successful combustion inside the cylinders of a diesel engine is dependent upon （）.

A.fine atomization
B.high temperature
C.good mixing of fuel and air
D.all of the above

单项选择题What occurs in the combustion space of a diesel engine cylinder shortly after ignition and before the piston reaches TDC?（）

A.Rapid increase in temperature with constant pressure
B.Rapid increase in pressure with constant temperature
C.Rapid increase in pressure and temperature
D.Rapid increase in volume and decrease in pressure

单项选择题The power output of a turbocharged diesel engine will drop if the cooling water flow through the after-cooler is interrupted because the （）.

A.turbocharger stalls
B.exhaust pressure increases
C.air charge density decreases
D.scavenge effect increases

单项选择题The diameter of a piston is usually less at the crown than at the skirt, in order to （）.

A.facilitate the installation of piston rings
B.allow for the expansion of the piston during operation
C.prevent crankcase vapors from entering the combustion chamber
D.reduce wearing of the upper cylinder liner