连云港海员培训基地2023年四小证培训计划表
连云港海员培训基地2023年四小证培训计划表
华洋海员
报名详询CE李老师：15817700717【微信同号】 报名详询CE李老师：15817700717【微信同号】
小证初培Z02精通艇阀2023年3月17日到2023年3月20日
报名详询CE李老师：15817700717
四小证更新2023年3月18日到2023年3月19日 www.hxseaman.com
四小证01基本安全初培训。培训时间12天2023年3月19日到2023年3月29日
华新海员
四小证Z07Z08船舶保安意识培训合格证和负有指定保安职责船员培训合格证2023年3月19日到2023年3月21日 幸福船员
单独大厨证,MLC厨师培训2023年3月22日到2023年3月24日 报名详询CE李老师：15817700717
小证初培Z04高级消防2023年3月22日到2023年3月26日 华新海员
一、单项选择题：
.液压调速器要设有刚性反馈机构，目的是保证在调速过程中具有一定的____ A
A. 稳定调速率 B. 瞬时调速率 C. 转速波动率 D. 稳定时间
2.在U-G8表盘式液压调速器中小反馈活塞的动作是由下列部件控制的：C
A.控制滑阀和调速弹簧B.浮动杆和大反馈活塞C.反馈弹簧和大反馈活塞D.飞重和滑阀
3.关于UG-8表盘式液压调速器的速度设定机构说法正确的是：B
A.调速电机通过调速旋钮设定转速B.调速电机轴与调速齿轮弹性连接
C.调速旋钮与调速齿轮弹性连接
D.顺时针转动调速旋钮设定转速降低
4.当UG-8型表盘式液压调速器进行供油量调节，使柴油机的转速稳定后，调速器内部 ____ 的位置发生变化。B
A. 小反馈活塞 B. 大反馈活塞 C. 反馈支点 D. 补偿针阀
5.WOOD WARD UG-8型表盘式液压调速器的表盘上设有四个旋钮，侧面设有一个反馈指针，转动 ____ 能够调节调速过程的稳定性。D
A. 转速指示器旋钮 B. 负荷限制旋钮 C. 调速旋钮 D. 反馈指针
6.两台并联工作的发电柴油机，如果出现负荷不能均匀分配的故障，则应该调节调速器的_____ 。A
A. 静速差旋钮 B. 反馈指针 C. 补偿针阀 D. 调速旋钮
7.WOOD WARD UG-8型表盘式液压调速器的表盘上设有四个旋钮，侧面设有一个反馈指针，转动 _____ 能够使柴油机停车。B
A. 静速差旋钮 B. 负荷限制旋钮 C. 调速旋钮 D. 反馈指针
8.转动UG-8表盘式液压调速器速度降旋钮调节静速差，其实质是改变了_____B
A.调速齿轮与静速差杆的连接位置B.静速差杆转动支点的位置C.静速差杆与输出轴的连接位置D.静速差杆的位置
9.UG-8表盘式液压调速器的负荷限制机构实现对负荷限制是通过：C
A.限制调速齿轮的位置B.限制动力活塞的动作C.限制滑阀的动作D.限制输出轴的位置
10.使用UG-8液压调速器的发电柴油机单机使用时如负荷限制旋钮限制较小，易产生的后果是：D
A.不能起动B.不能调速C.飞车D.停车
11. 对UG-8调速器进行稳定性调节的要求是：D
A.在柴油机空车时调节B.在柴油机有负荷时调节
C.先有负荷调节再空车调节D.先空车调节再有负荷调节
12. 对UG-8调速器进行下列哪项调节时有飞车的危险：B
A.调整静速差B.调整稳定性C.调整负荷限制D.B+C
13. 对UG-8调速器稳定性调节的正确操作是：A
A.将反馈指针拨至某一位置然后调节针阀的开度B.将针阀开至1/4~1/2圈然后调节反馈指针
C.同时调节反馈指针和针阀开度D.将针阀开至1/16~2圈然后调节反馈指针
14.对UG-8表盘式液压调速器如果用配电板上的调速旋钮可以控制调速器上的调速电机转动，但不能调速，而手动旋钮可以调速，原因可能是：C
A.调速齿轮卡死B.调速杆卡死
C.调速机构摩擦离合器故障D.控制滑阀卡死
15.关于PGA液压调速器手动转速设定说法正确的是：A
A.有最大转速设定值且该值可调B.有最小转速设定值且该值可调
C.既有最大转速设定值也有最小转速设定值且都可调
D.既有最大转速设定值也有最小转速设定值，最大值可调最小值不可调
16.关于PGA液压调速器的气动转速设定说法正确的是：C
A.设定转速的高值可调，低值不可调B. 设定转速的低值可调，高值不可调
C.设定转速的高、低值都可调D.设定转速的高、低值都不可调
17.PGA液压调速器运转中突然无转速设定气压信号时柴油机将会：B
A.停车 B.停车或低速运转，取决于调速器的设定
C.停车或低速运转，取决于手动转速设定旋钮的位置
D.低速运转
18.PGA液压调速器最高转速限制的限制方式是：B
A.由手动高速调节螺钉限制B.由转速设定油缸上的最高转速限制阀限制
C.由设定转速的最高气压限制
D.由限制转速设定伺服活塞最高位置的止动调节螺钉限制
19.PGA液压调速器当转速设定气压信号达最大值而转速没达到要求值，正确的调节是：B
A.向转速设定油缸方向移动复位杆的可调支点
B.向远离转速设定油缸方向移动复位杆的可调支点
C.向上移动复位杆的可调支点D.向下移动复位杆的可调支点
20.关于表盘式调速器调速旋钮的使用说法正确的是：D
A.起动时为防转速冲得过高，可顺时针转动调速旋钮将转速调低
B.调速旋钮只能在一圈内转动调节
C.调速旋钮可多圈转动调节，但用调速电机调速前必须恢复调速旋钮的位置
D.发电柴油机并网运行时一般不用手动旋钮调速
21.液压调速器长期存放时，要求是：C
A.干存放B.内部零件表面涂润滑脂存放
C.灌满调速器润滑油存放D.灌满轻柴油存放
22.液压调速器换油时，旧油的放出应在哪一时刻进行：B
A.空车正常转速运转时B.停车后油热时C.停车后油冷却时D.空车怠速运转时
23.关于液压调速器的清洗，说法不正确的是：D
A.可用轻柴油清洗B.可从机器上拆下清洗
C.可在机器上清洗D.在机器上清洗时，机器不能运转
24.如果没有合适的调速器专用液压油，可用 _____ 来替代。A
A. 增压器润滑油 B. 主机系统油 C. 主机气缸油 D. 分油机齿轮箱油
25.液压调速器传动齿轮部分齿牙折断对转速调节的影响是：A
A.转速调节不稳定B.不能调速C.停车D.飞车
26.在采用空气马达启动柴油机的启动空气系统中，不需要____ B
A. 启动控制阀与主启动阀 B. 空气分配器与气缸启动阀
C. 启动控制阀与气缸启动阀 D. 主启动阀与空气分配器
27.在压缩空气启动系统中，启动控制阀的作用是控制________的开启和关闭。D
A. 空气分配器 B. 气缸启动阀 C. 空气压缩机 D. 主启动阀
28.采用双气路气缸启动阀的目的是________。C
A. 在启动和制动时，当气缸内的压力超过启动空气的压力，气缸启动阀自动关闭
B. 在启动和制动时，当气缸内的压力超过启动空气的压力，气缸启动阀保持开启
C. 在启动时，当气缸内的压力超过启动空气的压力，气缸启动阀自动关闭
D. 在制动时，当气缸内的压力超过启动空气的压力，气缸启动阀自动关闭
29.二冲程柴油机某缸气缸起动阀卡死不能开启而使曲轴停在某一位置不能起动时，查看飞轮刻度可以确定发生故障的起动阀，下列说法正确的是：D
A.飞轮指示在下止点前0~120°的缸为故障缸
B.飞轮指示在上止点的缸为故障缸
C.飞轮指示在上止点前0~120°的缸为故障缸
D.飞轮指示在上止点后0~120°的缸为故障缸
30.四冲程柴油机某缸气缸起动阀卡死不能开启而使曲轴停在某一位置不能起动时，下列说法正确的是：B
A.飞轮指示在上止点后0~140°的缸为故障缸
B.飞轮指示在上止点后0~140°进排气阀都关闭的缸为故障缸
C.飞轮指示在上止点后0~140°排气阀关闭的缸为故障缸
D.飞轮指示在上止点后0~140°的缸为故障缸
31.某发电柴油机发生启动故障，现象是操作启动手柄启动时，各缸启动阀同时有压缩空气进入气缸，则故障出在 _____ 上。C
A. 启动控制阀 B. 主启动阀 C. 空气分配器 D. 气缸启动阀
32.柴油机某缸起动空气分配器滑阀卡死不能开启而影响起动时，检查和判断故障滑阀的正确方法是：D
A.盘车检查，滑阀滚轮不能落于凸轮凹弧工作段的滑阀为故障滑阀
B.冲车时泄气口没有空气泄出的滑阀为故障滑阀
C.冲车时滑阀滚轮不能落于凸轮凹弧工作段的滑阀为故障滑阀
D.B+C
33.起动手柄推至起动位置柴油机不能用压缩空气起动，可能的故障有：D
Ⅰ起动控制阀不开启 Ⅱ主起动阀不开启 Ⅲ某缸空气分配器滑阀不开启 Ⅳ某缸气缸起动阀不开启 Ⅴ盘车机没脱开 Ⅵ起动空气压力过低
A. Ⅰ、Ⅱ、Ⅴ、Ⅵ B. Ⅱ、Ⅲ、Ⅳ、Ⅵ C. Ⅰ、Ⅱ、Ⅴ、D.Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ
34.起动手柄推至起动位置柴油机不能用压缩空气起动，但换向后能起动，可能的故障有：B
Ⅰ起动控制阀不开启 Ⅱ主起动阀不开启 Ⅲ某缸空气分配器滑阀不开启 Ⅳ某缸气缸起动阀不开启 Ⅴ盘车机没脱开 Ⅵ起动空气压力过低
A.Ⅰ、Ⅱ、Ⅴ、Ⅵ B.Ⅱ、Ⅲ C.Ⅰ、Ⅱ、Ⅴ、D.Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ
35.新型MANB&W柴油机换向时不需使凸轮轴相对曲轴转动，这种柴油机需换向的设备有：D
A.喷油泵B.空气分配器C.排气阀D.A+B
36.新型MANB&W柴油机换向时凸轮轴相对曲轴位置不变，靠改变滚轮在凸轮上的角度实现换向的设备是：A
A.喷油泵B.排气机构C.空气分配器D.A+C
37.柴油机换向到位是指：B
A.换向手柄推至换向位置B.凸轮相对曲轴的位置转换到位
C.换向控制阀换到位D.柴油机反向运转
38. MAN.B&W MC型主机在换向时，_______不必换向。D
A. 高压油泵 B. 空气分配器 C. 进气阀 D. 排气阀
39.根据有关规定，在驾驶台、集控室和机旁操纵台必须设有主机的_______ 。D
A. 起动操纵机构 B. 离合器脱合机构 C. 喷油量调节机构 D. 应急停车按钮或手柄
40.测取示功图时，下列说法错误的是：D
A.测取示功图时应画好大气压力线 B.示功阀漏气时画大气压力线不准
C.大气压力线是量取压力的依据D.大气压力线是计算功率的依据1. Any carbon built up on surfaces must be washed away by _____ additives and held in suspension by a _____ additive.
A. dispersant /detergent B. detergent/dispersant
C. dispersant /dispersant D. detergent/detergent2. _____ power is the power developed within the cylinder and can be measured by an engine indicator.
A. The shaft B. The mechanical C. The electric D. The indicated3. Which of the following can be obtained by means of an indicator card?
A. the peak pressure in a cylinder. B. the temperature of the cooling water.
C. the fuel consumption. D. None of the above.4. Acid solution ______ in the system can be tested from time to time by putting some on to a piece of lime.
A. strength B. dense C. percentage D. velocity5. The device allowing for the change in volume of the cooling water in a propulsion diesel engine closed cooling system is the _____.
A. fresh water expansion tank B. sea water expansion tank
C. thermostatic expansion valve D. jacket water cooler accumulator6. Which of the following statements is correct concerning the viscosity of lubricating oil?
A. Viscosity will increase as temperature increases.
B. Viscosity is a measure of a fluid's internal resistance to flow.
C. Viscosity will decrease as temperature decreases.
D. Viscosity is not dependent on temperature.7. According to the way the energy of the exhaust gases is utilized, pressure-charging can be divided into two main systems, namely, the constant-pressure system and _____.
A. the pulse-phase system B. the pulse Doppler system
C. the pulse system D. the pulse interval8. The work fuel does in each working cycle can be obtained by taking the _____.
A. precautions B. rpm C. indicator cards D. B and C9. _____ in what position the engine stops there will always be at least one of the cylinders with its starting air valve open to admit compressed air to start the engine.
A. Because B. Owing to C. For D. No matter10. The position of the piston parts in relation to each other is secured by means of _____ in the crown.
A. a mark B. a bolt C. a dowel pin D. a measuring tool11. By which of the following means is force efficiently provided to vary the pitch of the blades on a modern controllable pitch propeller?
A. Hydraulic B. Mechanical C. Pneumatic D. Electrical12. The required amount in the change of speed necessary before a governor will make a corrective movement is known as _____.
A. speed droop B. sensitivity C. stability D. promptness
13. A mono-pump is a single-screw pump. That means it consists of _____ rotor(s).
A. one B. two C. three D. four14. The discharge head of a centrifugal pump will vary directly with the _____.
A. change in impeller diameter
B. square of the impeller diameter
C. cube of the impeller diameter
D. impeller efficiency for large changes in the size of the impeller15. Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid _____ pressure.
A. depending on B. in relative to C. regardless of D. because of16. As the air passes through the charge air cooler, its temperature may be reduced and moisture condensed, with the condensate in danger of being carried into the engine. So a water separator should be mounted beneath the bottom part of the engine inlet manifold. A water separator is used in order to _____.
A. keep the air from being carried into the engine
B. keep the moisture from being condensed
C. keep the danger from being carried into the engine
D. take away the condensate from the air17. The amount of fluid delivered by a screw pump can be regulated by _____.
A. throttling the pressure line B. changing the speed of the rotor
C. either A or B D. None of the above is true.18. Strainers, sometimes called _____, are devices designed to prevent the passage of unwanted solids into or further along a system.
A. dampers B. filters C. stopper circuits D. separators19. Improper maintenance of an automatic auxiliary boiler oil burner could result in _______.
A. fuel pump failure B. fan motor failure
C. increased feedwater consumption D. decreased boiler efficiency20. As for a oil-fired boiler too much air would indicated by _____.
A. yellowish flame B. golden yellow flame
C. milky flame D. brilliant white flame21. Prior to lighting off a cold automatically fired auxiliary boiler, you should _____.
A. check and regulate the water level B. close the air cock once fires are lit
C. blowdown the gage glass D. crack the steam stop to assure protective steam flow22. To start the ejection process the oil feed to the centrifuge is first shut off and the oil remaining in the bowl removed by admitting _____.
A. flashing water B. operating oil C. flushing water D. sealing water23. They understand the _____ of automatic sludge discharging of the purifier. But they are not good in practice.
A. principle B. principal C. theory D. case24. The principle of separation by which all commercially available oily water separators function is _____ differential between oil and water.
A. the temperature B. the viscosity C. the gravity D. the size25. The oil sludge is burnt in the _____onboard. I’ll show you the ashes.
A. boiler B. main engine C. auxiliary engine D. incinerator26. A class ‘ C ’ fire would occur in_____.
A. bedding B. pipe insulation C. paint D. a generator27. If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should _____.
A. add fluid that is the same color as the fluid in the reservoir
B. add turbine oil because it is always a good substitute
C. add any oil that has the same viscosity as the hydraulic fluid
D. check the winch manufacturer's instruction book28. No specific period is given for the renewal of the lubricating oil filter element as this should be done _____a figure of 0.7 bars is shown on the gauge.
A. whatever B. whenever C. wherever D. whoever29. With reference to operating a four-ram steering gear system under emergency conditions, which one of the following statements is incorrect ?
A. Only one pump should be used at any time
B. The ship speed should be reduced to 70% of the normal
C. Watch keeping of the steering gear should be increased
D. Limitations of the steering gear should be logged but the bridge need not be informed30. When the water produced from most evaporator is supplied for drinking purpose, it must be treated to ensure it is biologically pure and _____.
A. slightly acidic B. slightly alkaline C. no salty D. slightly bitter31. Excessive lube oil consumption by a reciprocating air compressor can be caused by _____.
A. using a slightly dirty air filter
B. using oil having an excessive viscosity
C. intercooler or after-cooler leaks
D. carrying the oil level higher than normal32. The primary task of the compressed air system is to deliver the starting air necessary for _____.
A. starting the M.E. B. starting the emergency electric alternator
C. driving the main turbine D. driving the turbocharger33. Sludge may form in the crankcase of an air conditioning compressor as a result of _____.
A. bubbling refrigerant B. overheating and oxidation
C. lowered operating temperatures D. reducing the cloud or flash point34. Which of the listed statements is correct concerning refrigeration systems?
A. Dehydrators must be used continuously in a refrigeration system.
B. A 25 ton refrigeration system has the same cooling effect as melting 25 tons of ice in 24 hours.
C. A thermostatic expansion valve is used to control refrigerated space temperature.
D. The liquid receiver functions to collect and remove non-condensable gases.35. Which of the statements listed concerning heat transfer is correct?
A. Heat is always transferred at a constant rate.
B. Heat transfer rate increases as temperature difference increases.
C. The rate of heat transfer is not affected by temperature difference.
D. The high temperature region is known as a heat sink.36. An excessive charge of refrigerant in an air-cooled refrigeration system can cause _____.
A. oil foaming in the compressor
B. higher than normal suction and discharge pressures with a higher box temperature
C. higher than normal discharge pressure with a normal box temperature
D. the compressor to run continuously37. When adding oil to a refrigeration system, precautions must be taken to ensure that _____.
A. the compressor suction pressure is not too high
B. all air is purged from the pump and charging fittings
C. the high pressure cutout switch is held open to prevent accidental starting
D. the condenser is completely shutdown first38. The staring current of an a.c. motor is _____the rated current.
A. the same as B. much larger than C. less than D. equals39. _____is used to produce electric power.
A. An alternator B. A fresh water generator C. A compressor D. A clarifier40. Generators should have an excitation/voltage regulation system which will enable them to share the steady state reactive load _____no machine exceeds its proportional share of reactive load by more than 10% of the rated reactive load of the largest generator.
A. when B. so as C. such that D. though41. Which of the following should be the FIRST step in removing a generator from parallel operation?
A. Trip the generator off the switchboard.
B. Turn off all electrical equipment.
C. Remove the load from the 'off going' generator.
D. Increase the cycles of the generator staying on the line.42. Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions?
A. The generator and bus transfer section B. The 450 volt, 60 cycle, 3 phase bus
C. The 120 volt, 3 phase, 60 cycle bus D. The 24 volt DC bus43. Temperature control valves installed in the jacket cooling water system of a diesel engine, modulates the rate of water flow through the _____.
A. cooling water pump B. nozzle cooling passages
C. cylinder jackets D. heat exchanger44. Which of the following marine examples belongs to the open loop control system?
A. accommodation heating system B. steering gear
C. boiler control D. cargo control45. The viscosity regulator controls the fuel oil temperature _____ provide oil at the correct viscosity for combustion.
A. in order that B. because of C. in order to D. owing to46. The unit of electrical power is the _____.
A. ampere B. kilovolt C. watt D. farad47. A transformer in an electric circuit serves to _____.
A. generate its own electrical power
B. transform electrical energy into mechanical energy
C. increase or decrease circuit voltage as required
D. convert AC current to DC current48. UMS stands for _____.
A. ultra much space B. universal medium system
C. unit machined space D. unattended machinery space49. Which of the following materials is a good insulator?
A. steel B. aluminum C. glass D. copper50. The fresh water generator produces fresh water_____.
A. by cooling sea water B. by heating sea water
C. by evaporation of sea water D. by purifying sea water51. White smoke exhausting from an operating diesel engine may indicate _____.
A. a cracked liner B. burning lube oil
C. an overloaded engine D. insufficient combustion air52. In a diesel engine, excessive cylinder liner wear will cause ______. I. increased blow-by II. wear between the piston ring and groove
A. I only is correct B. II only is correct
C. both I and II are correct D. neither I or II are correct
53. Poor combustion in a diesel engine can be caused by_____.
A. high compression pressure B. low intake air temperature
C. low exhaust pressure D. high scavenge air temperature54. If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because the_____.
A. cylinder compression pressure may not be high enough
B. cylinder compression temperature may be too high
C. fuel oil injection pressure may not be high enough
D. scavenge and purge process is incomplete55. Hearing a strong noise, _____at once.
A. the engine stopped B. the engine was stopped
C. he stopped the engine D. he had stopped the engine56. Each journal and pin should be examined for _____and grooving.
A. bridges B. recesses C. rears D. ridging57. Combustion knock can occur in the cylinders of a diesel engine under any condition permitting _____.
A. a shortened ignition delay period B. a lean fuel/air mixture
C. excess fuel in the combustion chamber D. rapid vaporization of injected fuel droplets58. Most conducting materials such as copper, aluminum, iron, nickel, and tungsten _____.
A. increase in resistance with increased temperature
B. increase in resistance with decreased temperature
C. decrease in resistance with increased temperature
D. increase in conductance with increased temperature59. The bearing cap and shell are replaced and tightened up until _____.
A. the “nip” is zero B. the “ nap” is zero
C. the“ gap” is correct D. the “ clearance” is correct60. Which of the motors for the devices listed below is fitted with an instantaneous overload relay?
A. Fan B. Pump C. Winch D. Machine tool61. _____, the engine must be stopped immediately.
A. Should knocking occur B. If knocking occur
C. Should if knocking occurs D. If occur knocking62. The resistance of electric wire will decrease as its _____.
A. length increases B. cross-sectional area increases
C. temperature increases D. percent of metallic purities increases63. It is well known that the whole power distribution of the ship’s electrical services mainly depend on the ___________.
A. sub-boards B. main switchboards C. emergency switchboards D. distribution boards
64. Fix the fuel injector into _____ after repair.
A. the cylinder liner B. the cylinder cover
C. the cylinder jacket D. the piston65. The data to be recorded on this sheet _____the performance of the engine.
A. makes the experts to judge B. enables the experts to judge
C. make the experts judging D. enable the experts to judge66. The value of GM still remains one meter, meanwhile we can pump the ballast water to _____the ship on even keel.
A. make B. put C. keep D. get67. When off loading garbage to another ship, your records must identify that ship by name and _____.
A. home port B. operator's name of record
C. official number D. master's name68. The order “Bow thrust stop.” means“_____”.
A. Bow thrust full to port B. Bow thrust full to starboard
C. No bow thrust revolutions D. No stern thrust revolutions二、关联题（每组关联题题干下有4个小题，每小题4个选项）
第一组：Generally people use diesel engines, gasoline engines or electrical motors to drive a modern ship．But none of them can work without oils． The burning of the oil in the cylinders of the diesel engine or gasoline engine provides the ship with driving power． The electrical motor runs on the electrical power． But the generator also consumes oil to produce this kind of power． Beside, the lube oil can reduce the friction between the moving parts of the engine and has much to do with its working condition．
69．Ｗhat do people use to drive a modern ship?
A． the wind B． the sail C．the oars D． the machines
70．Which of the following does not directly burn oil?
A． a gasoline engine B． a diesel engine C．an electrical motor D． none of them
71．What does a generator provide?
A． driving power B． a great deal of heat C． friction D．electricity
72．What’s the function of the lube oil?A． to take away the heat B．to reduce friction
C． to remove the detritus D． all of the A.B.C第二组：The usual coolant is fresh water, sea water is not used directly as a coolant because of its corrosive action． Lubricating oil is sometimes used for piston cooling since leaks into the crankcase would not cause problems． In some type of engines, the pistons are also cooled with fresh water． But difficulties caused by the leakage of piston cooling water have resulted in the wide use of lubricating oil for piston cooling．
73．The oil is used for piston cooling because____ ．
A． it is difficult to avoid the leakage of piston cooling water
B． it is difficult to use fresh water for the piston cooling
C． fresh water is used for piston cooling only in some type of engine
D． difficulties have been caused by the leakage of piston cooling oil
74．From this paragraph we can see that ____ ．
A． the usual coolant for piston cooling is fresh water or lubricating oil
B． the usual coolant for piston cooling is sea water or lubricating oil
C． fresh water is wide used for piston cooling
D． the usual coolant for piston cooling is fresh water or sea water (送分)
75．Sea water is never used directly as a coolant because of ____ ．
A． corrosive action of sea water B． corrosive action of fresh water and sea water
C． leakage of lubricating oil D． it is difficult to use sea water for the piston cooling
76．Which liquid is widely used as coolant of piston cooling?
A． Sea water B． Fresh water
C． Lubricating oil D． Oil or sea water （送分）三、中译英（共2题，请将答案写在答题纸上）
77. 各系统的温度与压力已保持在正常范围内，所有辅机均处于备航状态。
78. 油泵一台检修。所有活塞、轴瓦和滚珠轴承检查并测量。磨损部件用船方备件换新，然后装妥。全套装置试车良好。
