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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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What is the action that a GMDSS Radio Operator should take when a DSC distress alert is received? （）
A . No action is necessary，as the DSC control unit will automatically switch to the NBDP follow-on communications frequency
B . The operator should immediately set continuous watch on the radiotelephone frequency that is associated with the frequency band on which the distress alert was received
C . The Operator should immediately set continuous watch on VHF channel 70
D . The Operator should immediately set continuous watch on the NBDP frequency that is associated with the frequency band on which the distress alert was received
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When in operation, it is unavoidable that a small amount of oil （） through leakage, and in order to compensate for these leaks the system is connected to a feed pump.
A . escapes
B . overheats
C . expands
D . accelerate
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When a boiler is operating, the water level in the gauge glass reads （） when the boiler is shut down.
A . lower than
B . higher than
C . as much as
D . the same a
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When ship navigating in rough sea, the correct operation is （）
A . navigating with a low diesel engine speed
B . navigating with a stable diesel engine speed
C . increasing the efficiency of propeller
D . increasing fuel injectio
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Upon a user’s first visit to the website， which two operations are always performed when the getSession method is called with no arguments in a servlet？（）
A . All URLs returned by the server are rewritten.
B . An HttpSession object is created if necessary.
C . The user name and password of the user are checked.
D . The session ID is stored in the HTTP response as a cookie.
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When the steering gear is in operation, you should （）.
A . check hydraulic oil levels every hour
B . check the rams for overheating
C . check for excessive oil leakage from rams
D . drain water from telemotor cylinders each watch
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A portable foam fire extinguisher is placed in operation by（）
A . turning it upside down
B . pressing the foam lever
C . squeezing the grip handle
D . opening the hose valve
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When a diesel engine is operate at partial load, as compared to full load ,a decrease will occur in the average （）
A . air quantity aspirated
B . fuel injection pressure
C . combustion pressure on the power stroke
D . compression on the compression stroke
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When normal operating pressure is applied to the hydraulic oil used in a high-pressure system, the oil （）.
A . viscosity will decrease
B . volume will increase
C . volume will decrease
D . pour point will be reduced
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Which action should be taken when an auxiliary boiler in is operation?（）
A . Clean all electrical connections
B . Lift the relief valves by hand
C . Inspect and clean all solenoid valves
D . Inspect for oil and water leak
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For many years marine centrifuges were designed for （） operation, that is the machines were run for a period during which solids accumulated in the bowlThe machine was stopped when the accumulated solids began to impair its performance.
A、purifying
B、batch
C、long period
D、temporary
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Which of the following actions should normally be taken during each watch when the auxiliary boilers is in operation?（）
A . clean the flame scanner photocell window
B . Inspect and clean all solenoid valves
C . lift the safety valves by hand
D . Inspect for oil or water leak
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Why will a two stage flash type distilling plant tend to operate more efficiently when operating in cold seawater?（）
A . The colder seawater passing through the condenser tube bundles of the various stages increases evaporator vacuum
B . The amount of heated feed water discharged from the feed water heater after cndenser is increased
C . Fewer non-condensable gases are created by the flow of colder seawater
D . More seawater is allowed to pass through the flint stage overflow weir
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The plunger in the fuel injector pump, usually operated by a （）, is driven up and down when working.
A . crankshaft
B . camshaft
C . piston rod
D . rack and pinio
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When operating the air supply system in a covered lifeboat the（）.
A . fuel supply valve should be closed
B . hatches，doors，and oar ports should be closed
C . air cylinder shut-off valve should be closed
D . engine should be shut off
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A vessel engaged in mine clearance operations is called（）.
A . a vessel restricted in her ability to maneuver
B . a vessel not under command
C . a vessel constrained by her draught
D . a vessel not under way
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An interlock in the remote operating valve line stops the valve （） when the engine turning gear is engaged.
A . to open
B . opening
C . open
D . opened
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Start-Up Diagnostics are a diagnostic routine that regularly operate automatically when the CNC is switched on.
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When an op-amp operates in a linear region, the op-amp should be with ( )
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Start-Up Diagnostics are a diagnostic routine that regularly operate automatically when the CNC is switched on.
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Which is a potential hazard when operate a machine tool?
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A BJT has measured dc current values of IB = 0.1 mA and IC = 8.0 mA. When IB is varied by 100 μA, IC changes by 10 mA. What is the value of the βac for this device？____（）
A．80
B．10
C．100
D．800
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A BJT has measured dc current values of IB = 0.1 mA and IC = 8.0 mA. When IB is varied by 100 μA, IC changes by 10 mA. What is the value of the βdc for this device（）
A．80
B．10
C．100
D．800
