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
A water pump can not supply water after startingIt may be caused by （）.
A
closed discharge valve
B
broken pipe line
C
worn shaft
D
both A and B
参考答案
参考解析
解析：
暂无解析
更多 “单选题A water pump can not supply water after startingIt may be caused by （）.A closed discharge valveB broken pipe lineC worn shaftD both A and B” 相关考题
考题
EThe need to feed a growing population is putting much pressure on the world’s supply of water. With 97% of the world’s water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. Although the idea of a water shortage（短缺）seems strange to someone fortunate enough to live in a high rainfull country, many of the world’s agricultural industries experience constant water shortages.Although dams can be built to store water for agricultural use in dry areas and dry seaons, the costs of water redistribution(重新分配)are very high. Notonly is there the cost of the engineering itself, but there is also an environmental cost to be considered. Where valleys(山谷)are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water many flow easily through pipes to fields,but it cannot be transported from one side of the world to the other. Each country must therefore rely on the management of its own water to supply its farming requirements.This is particularly troubling ro countries with agricultural industries in areas dependent on irrigation（灌溉）. In Texas, farmers’ overuse of irrigation water be resulted in a 25% redcution of the water stores. In the Central Valley area of south eastern USA, a huge water engineering project provided water for farming in dry vallege, but much of the water use has been poorly managed.Saudi Arabia’s attempts to grow wheat in desert areas have been the pumping of huge quantities of irrigation water from underground reserves. Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping will see them run dry.72. From the first two paragraphs we learnt that _______.A.much of the world’s water is available for useB.people in high rainfll countries feel luckyC.the costs of water redistribution should be consideredD.water can be easily carried through pipes across the world
考题
The text is mainly about .A.water supply and increasing populationB.water use management and agricultureC.water redistribution and wildlife protectionD.water shornages and environmental protection.
考题
According to the last paragraph, the fourth way is "of a different kind" because（ ）[A] the first three ways can increase the water supply, while the fourth one can't[B] the first three ways can make a better use of water, while the fourth one can't[C] the first three ways is technology-based, while the fourth one is market-based[D] the first three ways can't balance the supply and demand of water, while the fourth one can
考题
If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.A.high steam pressure in the boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity
考题
A centrifugal pump may fail to deliver water when first started if the ______.A.water seal pipe is pluggedB.pump is not primedC.seal ring is properly locatedD.impeller is flooded
考题
单选题If separating effect is not good, which measure should be taken （）A
working at intervals and properly heatingB
warming up to 70℃, increase water supply flowC
improving impulse of water supplyD
reducing water supply flow
考题
单选题If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be （）A
a dirty lube oil strainerB
internal water leaksC
an oil suction line restrictionD
excessive wears of the cooling water pump
考题
单选题A water pump can not supply water after startingIt may be caused by （）.A
closed discharge valveB
broken pipe lineC
worn shaftD
both A and B
考题
单选题Which pump installation would require an external source of sealing water?（）A
Main circulator pump jacket water coolingB
Salt water service pumpC
Auxiliary condensate pumpD
Bilge pump
考题
单选题The value of GM still remains one meter, meanwhile we can pump the ballast water to（） the ship on even keel.A
makeB
putC
keepD
get
考题
单选题The SOLAS convention prescribes that in the fire fighting drill the duty engineer should start the pump and supply deck water in（） minute(s).A
5B
3C
2D
1
考题
单选题After stopping oily water separator, sea water should be permitted for （） minutes,（）should be closed after stopping pump to reduce oxidation corrosion of inner wall.A
15；inlet valueB
15；inlet and outlet valueC
30；inlet valueD
30；inlet and outlet value
考题
单选题Excessive vibration of an automatically fired auxiliary boiler can be caused by （）A
air or water in the furnaceB
combustion pulsesC
fuel oil pump failureD
flame failure
考题
单选题The reciprocating pump can’t draw water from a tank may be caused by （）.A
leaky pipeB
opened inlet valveC
too much water in tankD
None of the above
考题
单选题A centrifugal pump may fail to deliver water when first started if the （）.A
water seal pipe is pluggedB
pump is not primedC
seal ring is improperly locatedD
impeller is flooded
考题
单选题You may find the time of slack water after low water in a certain port from（）.A
Deadweight ScaleB
Tide TablesC
Notices to MarinersD
Table of Azimuth
考题
单选题Because the flow rate of supply water pump is too large, oily water separator does not work wellWhich of the following is not the reason?（）A
the monitoring equipment is out of orderB
separating effect becomes badC
inner wall is contaminatedD
separating effect becomes bad and inner wall is contaminated
考题
单选题One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）A
seal water supply be cut offB
make up water supply be cut offC
oil outlet valve closed or not open sufficientlyD
the flow rate of oily water is too much
考题
单选题Lube oil in the fresh water cooling system of a diesel engine may result from a （）A
camshaft seizureB
lube oil pump failureC
lube oil cooler failureD
lube oil pump overflow
考题
单选题The separating effect of oil separator is not very good, the reason may be（）A
too little seal waterB
improper gravity discC
oil discharging pump not working very wellD
low water level of the working water
考题
单选题If separating effect is not good, we can improve it by （）A
flushing separator with hot waterB
increasing water supply flowC
heat oily water properlyD
opening manual oil discharge value
考题
单选题Water accumulation in the cylinder of a secured engine is an indication that the （）A
soft water pump was not secured along with the engineB
jacket water thermostat has failedC
cylinder liner may be crackedD
raw water pump is over-speeding just prior to engine shutdown
考题
单选题If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.A
high steam pressure in the boilerB
abnormally high feed water temperatureC
abnormally high boiler water temperatureD
steam demand exceeding feed pump capacity
考题
单选题A centrifugal pump can’t supply water after startingYou should check （）.A
priming waterB
power supplyC
packing glandD
bearing lubrication
考题
单选题The blowers of an inert gas generation system aboard a tanker，will be automatically secured if（）.A
normal water supply at the water seal is lostB
the temperature of the inert gas being delivered to the cargo tanks is more than 150°FC
the cooling water supply to the scrubbers is lostD
all of the above
考题
单选题Which of the following conditions may need to be reduced when operating a large, low speed, main propulsion, diesel engine at low loads?（）A
Injection pressuresB
Control air supply pressureC
Cooling water flow through after-coolersD
Lube oil temperature
热门标签
最新试卷