单项选择题
A.decrease only B.increase only C.decrease slightly then returned to original speed D.increase slightly then returned to original speed
The arrangement and shape of the cams on a diesel engin...
单项选择题The arrangement and shape of the cams on a diesel engine camshaft directly control which of the listed groups of operating conditions?（）
A.speed, torque, and horsepower production B.firing order, valve timing, and valve lift C.fuel consumption, efficiency, and cylinder pressure D.scavenge pressure, compression ratio, and exhaust pressure
Corrosion inhibitors and/or soluble oils are added to d...
单项选择题Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to （）
A.maintain low pH in the cooling water B.reduce the cooling water temperature C.increase cooling water hardness D.form a protective film on metal surfaces
Fuel droplets injected into a diesel engine cylinder mu...
单项选择题Fuel droplets injected into a diesel engine cylinder must have adequate penetration to （）
A.prolong the ignition delay period B.ensure the beginning of fuel injection C.thoroughly utilize the air charge D.allow controlled fuel combustion
