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Normally，water boils at at _________of 100℃．
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Cylinders of marine diesel engines are normally cooled by ___ .A.sea waterB.fine mineral oilC.sanitary waterD.fresh water
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The number and position of hydrants arranged on board shall be such that _______，one of which shall be from a single length of hose，may reach any part of the ship normally accessible to the passengers or crew while the ship is being navigated．A.at least two jets of water which shall be from the same length of hoseB.at least two jets of water emanating from the same hydrantC.at least two jets of water not emanating from the same hydrantD.at least two jets of water not emanating from the same hydrant，one of which shall be from a single length of hose
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The function of the sentence ---Water boils at 100 degrees Centigrade is ______.A.interrogative
B.directive
C.informative
D.performative
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第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.The word"fraction"in the second paragraph means________.A:a large areaB:a very small amountC:an important systemD:a major source of information
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第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.Most of the fresh water on Earth________.A:is in the form of ice at the poles and on mountainsB:is stored undergroundC:is found in rivers and lakesD:comes from the rain
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共用题干
第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.There is more of rainfall________.A:over the mountains than over the riversB:over the rivers than over the mountainsC:over the land than over the oceansD:over the oceans than over the land
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单选题Water allowed to accumulate in the hydraulic system oil will cause an oxidation process producing by- products which are normally （）.A
gums, acids, and varnishesB
removed by cellulose type filtersC
neutralized by oil additivesD
not removed by absorbent filters
考题
问答题The second most important constituent of the biosphere is liquid water.This can only exist in a very narrow range of temperatures, since water freezesat 0℃ and boils at 100℃ This is only a tiny range compared with the low tem-peratures of some other planets and the hot interior of the earth, let the tem- 1．_______perature of the sun. As we know, life would only be possible on the face of a 2．_______planet had temperatures somewhere within this range. 3．_______ The earth’s supply of water probably remains quite fairly constant in 4．_______quantity. A certain number of hydrogen atoms, which are one of the mainconstituents of water, are lost by escaping from the atmosphere to out space, 5．_______but they are probably just about replaced by new water rising away from the 6．_______depths of the earth during volcanic action. The total quantity of water is notknown, and it is about enough to cover the surface of the globe to a depth of 7．_______about two and three-quarter kms. Most of it—97%—is in the form of the saltwaters of the oceans. The rest is fresh, but three quarter of this is in the form of 8．_______ice at the Poles and on mountains, and cannot be used by living systems when 9．_______melted. Of the remaining fraction, which is somewhat fewer than 1% of the 10．_______whole, there is 10-20 times as much stored as underground water as is actual-ly on the surface. There is also a minor, but extremely important, fraction ofthe water supply which is present as water vapour in the atmosphere.欢迎使用ueditor!
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单选题When steam is being raised on a boiler, the water level will normally （）.A
drop as the boiler warms upB
rise as the boiler warms upC
remain unchanged until the boiler is hot enoughD
rise and fall with the steam demand
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单选题If the beacon is mounted at a wrong place, it may（）by sea water, chemicals, exhaust and vibrations.A
be damagedB
work normally regardless of harmful conditionsC
not wok though it is not in a bad condition
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单选题During the diesel engine running, the water level of F.W expansion tank should normally kept in the （） level of glass tube.A
the highestB
above 3/4C
1/2 -3/4D
the lowest
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单选题Normally，potable water systems are connected directly to the（）.A
fire-main systemB
feed-water systemC
freshwater sanitary systemD
domestic water tank
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单选题Which step should normally be taken FIRST by those who have boarded a liferaft in an emergency?（）A
Ration food and water suppliesB
Take anti-seasickness pills，if availableC
Determine position and closest point of landD
Check pyrotechnic supplies
考题
单选题Cylinders of marine diesel engines are normally cooled by （）.A
sea waterB
fine mineral oilC
sanitary waterD
fresh water
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单选题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 windowB
Inspect and clean all solenoid valvesC
lift the safety valves by handD
Inspect for oil or water leaks
考题
单选题During the diesel engine running, the water level of FW expansion tank should normally kept in the （） level of glass tube.A
the highestB
above 3/4C
1/2-3/4D
the lowest
考题
单选题Because of the reduced （） in the vacuum boiling evaporator, some of the sea water boils as it flows through the tubes.A
temperatureB
water levelC
pressureD
rate of flow
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单选题In a normally operating diesel engine, the main cause of lubricating oil contamination in the crankcase is a result of the （）.A
metal particles loosened by wearB
air when no air cleaners are usedC
condensation of water vaporsD
breakdown of the lubricating oil by dilution
考题
单选题When water is used to fight a fire on board a ship，the effect of the weight of the water must be taken into account. How much sea water will increase the weight displacement by one ton?（）A
64 cubic feetB
35 cubic feetC
100 gallonsD
500 liters
考题
单选题Which of the following methods is normally used to control the temperature of air distributed from individual cooling coils in an air conditioning system using a chilled water circulation system?（）A
A room thermostat activates an electric heater at each individual chilled air outlet when necessaryB
Varying the number of passes the air makes across the coilsC
Varying the temperature of the water through the coilsD
Varying the quantity of water flowing through the coils
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单选题The stability of a vessel is normally the greatest when all fuel and water tanks are full because the （）.A
center of gravity is loweredB
center of buoyancy is loweredC
reserve buoyancy is unchangedD
hull freeboard is increased
考题
单选题Because of the reduced （）in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.A
pressureB
temperatureC
densityD
volume
考题
单选题During loading and discharging operations，in addition to when the cargo tanks have been properly filled，each inert gas system must be capable of maintaining a minimum gas pressure of（）.A
150 millimeters of water pressureB
125 millimeters of water pressureC
100 millimeters of water pressureD
75 millimeters of water pressure
考题
单选题A refrigerant boils and vaporizes in the （） in a compression refrigeration system.A
liquid receiverB
compressorC
condenserD
cooling coil
考题
问答题You are trying to fill a bath with both taps on, but have accidentally left out the plug. Normally the hot water tap takes 8 minutes to fill the bath and the cold water tap takes 10 minutes. However, the water empties out through the plug hole in 5 minutes. How long will it take for the bath to fill?
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