网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
The crankcases of many diesel engines are kept under a slight vacuum to （）
A
improve fuel economy
B
increase the air charge velocity
C
reduce the risk of explosion
D
all of the above
参考答案
参考解析
解析：
暂无解析
更多 “单选题The crankcases of many diesel engines are kept under a slight vacuum to （）A improve fuel economyB increase the air charge velocityC reduce the risk of explosionD all of the above” 相关考题
考题
An efficient seal between the cylinder block and cylinder heads on many diesel engines is obtained with________.A.graphite packingB.sealing compoundC.lubricating oilD.gaskets
考题
All diesel engines are classified as ______．A.Four cycleB.Compression ignitionC.Vacuum ignitionD.External combustion
考题
单选题Generally，you can best keep a vessel under steering control when the vessel has（）.A
HeadwayB
SternwayC
No way on，with engines stoppedD
No way on，with engines full ahead
考题
单选题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of （）A
less even torqueB
higher cylinder head temperaturesC
fewer power strokes per revolutionD
greater weight/size requirements
考题
单选题In modern installations, the main engine and the standby auxiliary engines（）A
can be started at low temperature and are free from preheatingB
usually are preheated by steam before being startedC
are kept at a constant temperature and free from preheatingD
are kept at a low temperature to save energy
考题
单选题Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）A
chromium plating piston ringsB
knurling the piston skirtC
extended maximum power operationD
applying load to a cold diesel engine
考题
单选题Diesel engines are considered safer than gasoline engines because（）.A
they are more heavily builtB
the fuel used is less volatileC
they can be easily reversedD
they operate at a lower speed
考题
单选题（）, so they are widely used on board ship nowadays.A
Diesel engines have more advantages in comparison with gasoline enginesB
Diesel engines have more advantages in comparison to gasoline enginesC
Gasoline engines have more advantages in comparison with diesel enginesD
Gasoline engines have more advantages in comparison to diesel engines
考题
单选题The cetane number rates fuels for diesel engines according to its （）A
antiknock characteristicsB
ignition qualitiesC
rates of vaporizationD
viscosity
考题
单选题The crankcase of many diesel engines are kept under a slight vacuum by the （）.A
scavenging action of the pistonB
piston type vacuum pump taking suction off a differential manometerC
gland exhausting manometerD
crankcase exhaust fan
考题
单选题Exhaust pipes for separate diesel engines can be combined only when （）A
space limitations prevent separately run pipesB
the engines are small auxiliary unitsC
they are arranged to prevent gas backflow to each engineD
a waste heat boiler is installed
考题
单选题The separation of impurities and water from （） is essential for good combustion of diesel engines.A
lube oilB
fuel oilC
turbine oilD
grease
考题
单选题Some diesel engines are supercharged with a （）A
slam chargerB
turbochargerC
fuel atomizerD
fuel injector
考题
单选题（） the engines, the diesel engine is（） used engine on board.A
Between；more commonlyB
Among；the most commonlyC
Between；not more commonlyD
Among；not the most commonly
考题
单选题An efficient seal between the cylinder block and cylinder heads on many diesel engines is obtained with（）A
graphite packingB
sealing compoundC
lubricating oilD
gaskets
考题
单选题A vessel’s Certificate of Documentation（）.A
may be retained by the owner at the home port OR kept on the vesselB
must be posted under transparent material in the pilothouseC
must be carried on boardD
must be kept on file at the corporate offices of the owner or operator
考题
单选题Diesel engines are started by supplying （） into the cylinders in the appropriate sequence for the required direction.A
cooling waterB
compressing airC
compressed airD
cylinder oil
考题
单选题All diesel engines are classified as（）.A
four cycleB
compression ignitionC
vacuum ignitionD
external combustion
考题
单选题The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the （）A
method of supplying airB
cooling systemC
method of igniting fuelD
valve operating mechanism
考题
单选题An auxiliary reservoir for starting auxiliary engines should be kept at （）.A
low pressure at all timesB
full pressure at all timesC
low pressure at intermittenceD
full pressure at intermittence
考题
单选题The responsibilities of the engineer officer in charge of the watch do not include （）A
to ensure the main propulsion plant are kept under constant surveillanceB
to ensure the auxiliary systems are kept under constant surveillanceC
to inspect the steering gear spaces at suitable intervalsD
to inspect and overhaul the equipments in his charge
热门标签
最新试卷