A water system for baths was built by over 3000 years ago（）

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• In a domestic fresh water system, the pump starters are controlled by （） switches which operate when the pressure in the tank varies within predetermined limits as water is drawn off.

  A . water level B . water flow C . temperature D . pressure

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• Cavitation erosion in the cooling water system of a diesel engine usually occurs at the pump impeller, and on the waterside of the （）

  A . fuel nozzle holders B . exhaust value guides C . engine cylinder liners D . low temperature and a low viscosity

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• The pH value of water in a diesel engine closed cooling water system should be maintained between （）.

  A . 60 to75 B . 80 to 95 C . 100 to 115 D . 120 to 135

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• Which of the following statements is correct for the design and installation of diesel engine cooling water systems?（）

  A . An alarm device with audible and visible signals is required for all cooling water systems B . Propulsion engines with bores over 200 mm are to be fitted with cooling water jackets C . Each totally enclosed cooling system shall be provided with a suitable head tank D . Drain cocks are to be provided at the lowest points of all cylinder water jacket

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• For the deepest water when rounding a bend in a river，you should navigate your vessel（）.

  A . toward the inside of the bend B . toward the outside of the bend C . toward the center of the river just before the bend，then change course for the river's center after the bend D . in the river's center

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• In a refrigeration system, if the cooling water to the condenser fails, the（）.

  A . box temperature solenoid valve will close B . expansion valve will close C . compressor will shutdown D . king valve will ope

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• In a diesel engine cooling water system, a pH of 60 indicates a/an （）.

  A . slightly acidic condition B . slightly alkaline condition C . overtreatment of water D . neutral condition of water

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• In a closed cooling water system, which of the problems can cause the water pressure to fluctuate?（）

  A . An open vent in the cooling system B . A fouled sea chest C . A restricted water passage in the engine D . Air entrained in the cooling water

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• Some vessels are equipped with a water lubricated stern robeWhen at sea, operating under normal conditions, the water service valve from the ships saltwater system to the bearing should be （）.

  A . closed, and no leakage permitted across the shaft packing B . closed, and only slight leakage permitted across the shaft packing C . open, and no leakage permitted across the shaft packing D . open, and only slight leakage permitted across the shaft packing

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• In a diesel engine cooling system, the high temperature alarm contact maker will be activated on excessively high water discharge temperature from the （）

  A . raw water pump discharge B . expansion tank outlet C . cooling water heat exchanger D . outlet engine jacket water outlet

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• （） allows for expansion and water make up in the water cooling system.

  A . A top tank B . A head tank C . A head valve D . A drain tank

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• In a closed cooling system for a turbocharged, four-stroke/cycle diesel engine, fluctuating water pressure can be caused by （）

  A . improper venting of the cooling system B . carrying the expansion tank water level too high C . a totally clogged impeller in the cooling water pump D . an incorrectly set cooling system temperature control

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• For the proper control of the air temperature in an air conditioning system using chilled water circulation, which of the listed conditions should remain constant regardless of load changes?（）

  A . Chilled water system supply temperature B . Chilled water system return temperature C . Compressor discharge temperature D . Compressor suction pressure

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• A diesel engine cooling water system with a pH factor of 30 indicates a condition of （）.

  A . slight acidity B . slight alkalinity C . excessive alkalinity D . excessive acidity

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• The jacket water temperature in a diesel engine closed freshwater cooling system is normally controlled by （）

  A . regulating the level of corrosion inhibitor in the primary cooling system B . the level of the freshwater expansion tank C . varying the engine load to meet temperature requirements D . the operation of the thermostatic valve

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• The most serious effect of air trapped in a diesel engine jacket water cooling system is that it（）.

  A . causes colloid suspension in the cooling water B . reduces the capability of the lubrication system C . can form pockets which block the flow of coolant through the system D . leads to the scuffing of cylinder wall

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• If the coolant temperature of a closed cooling water system for a diesel engine gradually increases, the trouble usually is （）

  A . a broken shaft on the freshwater pump B . an excessive accumulation of scale exchanger C . an incorrect thermostatic element operating range D . lube oil in the cooling water

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• An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.

  A . restriction in refrigerant piping B . air and non-condensable gases in the condenser C . water in the refrigerant D . flooding back of liquid refrigerant from the evaporator

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• A rigid lifesaving device only designed for survivors to hold on to while in the water is a（）.

  A . liferaft B . life float C . life preserver D . buoyant apparatu

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• Given the same water depth and line tension，the holding power of a 19 pound/foot wire rope mooring system in comparison to the holding power of a 90 pound/foot chain mooring system will be（）.

  A . weaker B . equal C . greater D . indeterminable

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• Before he set up Genera, Dr Patton had worked for a British water company.

  A．Right B．Wrong C．Not mentioned

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• The goods are now ready for（)．A．woolB．water proofC．packingD．Virus

  The goods are now ready for()． A．wool B．water proof C．packing D．Virus

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• 下面代码的输出结果是（）。 for a in ["torch","soap","bath"]: print（a)

  A．A.torch,soap,bath B．B.torch soap bath, C．C.torch,soap,bath, D．D.torch soap bath

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• 若打印图形 * 实现代码如下。 *** ***** ******* for （int i=1 ; i＜= a ; i++) { for （int j="1;" j++) system.out.print（“*”); system.out.print（“\n”); } a处为（＞ A、3

  B、4 C、5 D、6

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