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单选题
As the ocean water changes to ice, it keeps the temperature（）falling too far.
A
with
B
into
C
besides
D
from
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更多 “单选题As the ocean water changes to ice, it keeps the temperature（）falling too far.A withB intoC besidesD from” 相关考题
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What keeps Grimsvotn still?A. The slow flow of waterB. The low water temperatureC. The thick glacierD. The water pressure
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As the ocean water changes to ice, it keeps the temperature______ falling too far.A、withB、intoC、besidesD、from
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
The purpose of mentioning the Weddell Sea is__________.
查看材料
A．to give an example of cold-water salinity
B．to point out the location of deep waters
C．to make a comparison between hot-water salinity and cold-water salinity
D．to show that the water in the Weddell Sea varies in salinity from place to place
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
Which of the following is not the cause of the decrease in the oceanic salinity?
查看材料A．Precipitation.
B．Rain and snow.
C．Formation of ice.
D．Addition of water by rivers.
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
It can be known from the passage that increase in the salinity of ocean water is caused by__________.
查看材料A．melting of sea ice
B．precipitation
C．evaporation
D．supplement of salt
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
Which of the following statements is TRUE according to the passage?
查看材料
A．Oceanic salinity has great effect on sea life.
B．Many factors combine to cause changes in oceanic salinity.
C．The movement of the water is related to the amount of salt.
D．The temperature of the water has much to do with the oceanic salinity.
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
This passage mainly tells us about__________.
查看材料A．the analysis of the salinity of ocean waters
B．the causes of the variation in oceanic salinity
C．the importance of the changes in oceanic salinity
D．the different forms of salts in ocean waters
考题
根据下列内容，回答201-205题。
When we analyze the salt salinity(盐浓度) of ocean waters, we find that it varies only slightlyfrom place to place. Nevertheless, some of these small changes are important. There are three basicprocesses that cause a change in oceanic salinity. One of these is the subtraction of water from theocean by means of evaporation. In this manner, the salinity is increased, since the salt stays be-hind. If this is carried to the extreme, of course, white salt would be left behind; this, by the
way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to theocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas ofhigh rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increasedby the subtraction of water by evaporation, or decreased by the addition of fresh water by precipi-tation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higherthan it is in other parts of the world where there is not as much evaporation. Similarly, in coastalregions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting ofsea ice. When seawater is frozen, the dissolved materials are left behind. In thismanner, seawaterdirectly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared.
Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing pro-cess, which increases the salinity of cold water. This heavy water sinks and is found in the deeperportion of the oceans of the world.
This passage mainly tells us about___________.A.the analysis of the salinity of ocean waters
B.the causes of the variation in oceanic salinity
C.the importance of the changes in oceanic salinity
D.the different forms of salts in ocean waters
考题
Which of the following statements is TRUE according to the passage?___________A.Oceanic salinity has great effect on sea life
B.Many factors combine to cause changes in oceanic salinity
C.The movement of the water is related to the amount of salt
D.The temperature of the water has much to do with the oceanic salinity
考题
The world's oceans have warmed 50 percent faster over the last 40 years than previously thought due to climate change,Australian and US climate researchers reported Wednesday．Higher ocean temperatures expand the volume of water,contributing to a rise in sea levels that is covering small island nations and threatening to destroy the low-lying,densely-populated low regions around the globe.
The study,published in the British journal Nature,adds to a growing scientific chorus of warnings about the pace and consequences rising oceans．It also serves as a corrective to a massive report issued last year by the Nobel-winning UN Intergovernmental Panel on Climate Change(IPCC),according to the authors.
Rising sea levels are driven by two things:the thermal expansion of sea water,and additional water from melting sources of ice．Both processes are caused by global warming．The ice sheet that sits atop Greenland,for example,contains enough water to raise world ocean levels by seven meters,which would bury sea-level cities from Dhaka to Shanghai.
Trying to figure out how much each of these factors contributes to rising sea levels is critically important to understanding climate change,and forecasting future temperature rises,scientists say．But up to now,there has been a puzzling gap between the projections of computer-based climate models,and the observations of scientists gathering data from the oceans.
The new study,led by Catia Domingues of the Centre for Australian Weather and Climate Research,is the first to reunite the models with observed data．Using new techniques to assess ocean temperatures to a depth of 700 meters from 1961 to 2003,it shows that thermal warming contributed to a 0.53 millimeter-per-year rise in sea levels rather than the 0.32 mm rise reported by the IPCC.
What was the main finding of the study?A.The warming of the world's oceans is not a threa
B.That not enough is being done about global warmin
C.There is a puzzling gap between the model and observation
D.Ocean waters have warmed faster than scientists had previously though
考题
The world's oceans have warmed 50 percent faster over the last 40 years than previously thought due to climate change,Australian and US climate researchers reported Wednesday．Higher ocean temperatures expand the volume of water,contributing to a rise in sea levels that is covering small island nations and threatening to destroy the low-lying,densely-populated low regions around the globe.
The study,published in the British journal Nature,adds to a growing scientific chorus of warnings about the pace and consequences rising oceans．It also serves as a corrective to a massive report issued last year by the Nobel-winning UN Intergovernmental Panel on Climate Change(IPCC),according to the authors.
Rising sea levels are driven by two things:the thermal expansion of sea water,and additional water from melting sources of ice．Both processes are caused by global warming．The ice sheet that sits atop Greenland,for example,contains enough water to raise world ocean levels by seven meters,which would bury sea-level cities from Dhaka to Shanghai.
Trying to figure out how much each of these factors contributes to rising sea levels is critically important to understanding climate change,and forecasting future temperature rises,scientists say．But up to now,there has been a puzzling gap between the projections of computer-based climate models,and the observations of scientists gathering data from the oceans.
The new study,led by Catia Domingues of the Centre for Australian Weather and Climate Research,is the first to reunite the models with observed data．Using new techniques to assess ocean temperatures to a depth of 700 meters from 1961 to 2003,it shows that thermal warming contributed to a 0.53 millimeter-per-year rise in sea levels rather than the 0.32 mm rise reported by the IPCC.
What happens when the ocean's temperature rises?A.It causes sea levels to ris
B.It causes sea levels to decreas
C.It causes sea levels to remain unchange
D.It causes sea flood all over the glob
考题
共用题干
What We Take From and Give to the SeaAs long as we have been on earth,we have used the sea around us.We take from the ocean,and we give to it.We take fishes from the ocean-millions of kilograms of fish,every year,to________(51)millions of people.We even_______(52)their bones for fertilizer.We take minerals from the ocean.One way to get salt is to_______(53)seawater in shallow basin and leave it until it evaporates（蒸发）.Along with salt,other minerals are left_______(54)evaporation.Much gold and silver drift dissolved in the waters of the sea,too.But the sea does not give them_______(55)by simple evaporation.________(56)gifts from the sea are pearls , sponges（海绵）and seaweed.Pearls________(57)jewelry.Natural sponges become cleaning aids.Seaweed becomes______(58)of many kinds一even candy,and ice cream一as well as medicine.Believe it or not,fresh water is another_______(59)from the sea.We cannot drink ocean water.Some of its contents may______(60)illness.But ocean water becomes fresh water when the salts are ________(61).In the future,we will find ourselves．________(62)more and more onfresh water from the sea.The sea_______(63)us food,fertilizer,minerals,water,and other gifts.What do we give the sea?Garbage.We pollute the ocean_______(64)we use it as a garbage dump.Huge as it is,the ocean cannot hold all the water that we pour into it.________(65)garbage into the ocean is killing off sea life.Yet as the world population grows,we may need the sea and its gifts more than ever._________65A:Reducing B:Collecting C:Removing D:Casting
考题
共用题干
What We Take From and Give to the SeaAs long as we have been on earth,we have used the sea around us.We take things from the ocean,and we give to it.We take fishes from the ocean-millions of kilograms of fish,every year,to feed millions of people.______(46)We take minerals from the ocean.One way to get salt is to place seawater in a shallow basin and leave it until it evaporates.______(47) Much gold and silver drift dissolved in the waters of the sea,too.But the sea does not give them up by simple evaporation.Other gifts from the sea are pearls,sponges and seaweed.Pearls become jewelry.______(48)Seaweed becomes food of many kinds-even candy,and ice cream-as well as medicine.Believe it or not,fresh water is another gift from the sea.We cannot drink ocean water.______(49)But ocean water becomes fresh water when the salts are removed.In the future,we will find ourselves depending more and more on fresh water from the sea.The sea gives us food,fertilizer,minerals,water,and other gifts .What do we give the sea?Garbage.______(50)Huge as it is,the ocean cannot hold all the water we pour into it. Dumping garbage into the ocean is killing off sea life.Yet as the world population grows,we may need the sea and its gifts more than ever.We are finally learning that if we destroy our sea,we might also destroy ourselves.Hopeful-ly,it is not too late.______(48)A: Natural sponges become cleaning aids.B: We pollute the ocean when we use it as a garbage dump.C: The area of the sea is becoming smaller and smaller.D: Along with salt,other minerals are left after evaporation.E: We even use their bones for fertilizer.F: Some of its contents may cause illness.
考题
共用题干
第一篇Arctic MeltEarth’s North and South Poles are famous for being cold and icy.Last year,however,the amnount of ice in the Arctic Ocean（北冰洋）fell to a record low.Normally,ice builds in Arctic waters around the North Pole each winter and shrinks（缩小）during the summer. But for many years,the amount of ice left by the end of summer has been declining.Since 1979,each decade has seen an 11.4 percent drop in end?of-summer ice cover. Between 1981 and 2000,ice in the Arctic lost 22 percent of its thickness,becoming I.13 meters thinner.Last summer,Arctic sea ice reached its thinnest levels yet.By the end of summer 2007,the ice had shrunk to cover just 4.2 million square kilometers.That's 38 percent less area than the average cover at that time of year. And it's a very large 23 percent below the previous record low,which was set just 2 years ago. This continuing trend has made scientists concerned.There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer（海洋学家）at the University of Washington at Seattle.Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic,leaving a large area of thin ice and open water.Scientists also suspect that fewer clouds cover the Arctic now than in the past.Clearer skies allow more sunlight to reach the ocean.The extra heat warms both the water and the atmosphere.In parts of the Arctic Ocean last year,surface temperatures were 3.5℃warmer than average and 1.5℃warmer than the previous record high.With both air and water getting warmer,the ice is melting from both above and below. In some parts of the Beaufort Sea,north of Alaska and western Canada,ice that measured 3.3 meters thick at the beginning of the summer measured just 50 centimeters by season's end.The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice covcrfrom above,says Donald K. Perovich,a geophysicist at the U.S.Army Cold Regions Researchand Engineering Laboratory in Hanover,N.H.Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.By the end of summer 2007 the ice cover in the Arctic was ________.A:4.2 million square kilometersB:11.4 million square kilometersC:1.13 million square kilometers D:38 million square kilometers
考题
共用题干
第一篇Arctic MeltEarth’s North and South Poles are famous for being cold and icy.Last year,however,the amnount of ice in the Arctic Ocean（北冰洋）fell to a record low.Normally,ice builds in Arctic waters around the North Pole each winter and shrinks（缩小）during the summer. But for many years,the amount of ice left by the end of summer has been declining.Since 1979,each decade has seen an 11.4 percent drop in end?of-summer ice cover. Between 1981 and 2000,ice in the Arctic lost 22 percent of its thickness,becoming I.13 meters thinner.Last summer,Arctic sea ice reached its thinnest levels yet.By the end of summer 2007,the ice had shrunk to cover just 4.2 million square kilometers.That's 38 percent less area than the average cover at that time of year. And it's a very large 23 percent below the previous record low,which was set just 2 years ago. This continuing trend has made scientists concerned.There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer（海洋学家）at the University of Washington at Seattle.Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic,leaving a large area of thin ice and open water.Scientists also suspect that fewer clouds cover the Arctic now than in the past.Clearer skies allow more sunlight to reach the ocean.The extra heat warms both the water and the atmosphere.In parts of the Arctic Ocean last year,surface temperatures were 3.5℃warmer than average and 1.5℃warmer than the previous record high.With both air and water getting warmer,the ice is melting from both above and below. In some parts of the Beaufort Sea,north of Alaska and western Canada,ice that measured 3.3 meters thick at the beginning of the summer measured just 50 centimeters by season's end.The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice covcrfrom above,says Donald K. Perovich,a geophysicist at the U.S.Army Cold Regions Researchand Engineering Laboratory in Hanover,N.H.Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.The Beaufort Sea mentioned in Paragraph 7 is an example to show_________. A:how acetirate the new measurements areB:how thick the ice is in itC:how serious the problem of the ice melt in the Arctic isD:how dangerous it is to travel to it
考题
共用题干
第一篇Arctic MeltEarth’s North and South Poles are famous for being cold and icy.Last year,however,the amnount of ice in the Arctic Ocean（北冰洋）fell to a record low.Normally,ice builds in Arctic waters around the North Pole each winter and shrinks（缩小）during the summer. But for many years,the amount of ice left by the end of summer has been declining.Since 1979,each decade has seen an 11.4 percent drop in end?of-summer ice cover. Between 1981 and 2000,ice in the Arctic lost 22 percent of its thickness,becoming I.13 meters thinner.Last summer,Arctic sea ice reached its thinnest levels yet.By the end of summer 2007,the ice had shrunk to cover just 4.2 million square kilometers.That's 38 percent less area than the average cover at that time of year. And it's a very large 23 percent below the previous record low,which was set just 2 years ago. This continuing trend has made scientists concerned.There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer（海洋学家）at the University of Washington at Seattle.Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic,leaving a large area of thin ice and open water.Scientists also suspect that fewer clouds cover the Arctic now than in the past.Clearer skies allow more sunlight to reach the ocean.The extra heat warms both the water and the atmosphere.In parts of the Arctic Ocean last year,surface temperatures were 3.5℃warmer than average and 1.5℃warmer than the previous record high.With both air and water getting warmer,the ice is melting from both above and below. In some parts of the Beaufort Sea,north of Alaska and western Canada,ice that measured 3.3 meters thick at the beginning of the summer measured just 50 centimeters by season's end.The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice covcrfrom above,says Donald K. Perovich,a geophysicist at the U.S.Army Cold Regions Researchand Engineering Laboratory in Hanover,N.H.Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.What are the reasons for the ice melting according to the scientists?A:Strong winds and clear skits.B:Longer summers and shorter winters.C:Open water and thin ice.D:Heavy clouds and light winds.
考题
共用题干
第一篇Arctic MeltEarth’s North and South Poles are famous for being cold and icy.Last year,however,the amnount of ice in the Arctic Ocean（北冰洋）fell to a record low.Normally,ice builds in Arctic waters around the North Pole each winter and shrinks（缩小）during the summer. But for many years,the amount of ice left by the end of summer has been declining.Since 1979,each decade has seen an 11.4 percent drop in end?of-summer ice cover. Between 1981 and 2000,ice in the Arctic lost 22 percent of its thickness,becoming I.13 meters thinner.Last summer,Arctic sea ice reached its thinnest levels yet.By the end of summer 2007,the ice had shrunk to cover just 4.2 million square kilometers.That's 38 percent less area than the average cover at that time of year. And it's a very large 23 percent below the previous record low,which was set just 2 years ago. This continuing trend has made scientists concerned.There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer（海洋学家）at the University of Washington at Seattle.Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic,leaving a large area of thin ice and open water.Scientists also suspect that fewer clouds cover the Arctic now than in the past.Clearer skies allow more sunlight to reach the ocean.The extra heat warms both the water and the atmosphere.In parts of the Arctic Ocean last year,surface temperatures were 3.5℃warmer than average and 1.5℃warmer than the previous record high.With both air and water getting warmer,the ice is melting from both above and below. In some parts of the Beaufort Sea,north of Alaska and western Canada,ice that measured 3.3 meters thick at the beginning of the summer measured just 50 centimeters by season's end.The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice covcrfrom above,says Donald K. Perovich,a geophysicist at the U.S.Army Cold Regions Researchand Engineering Laboratory in Hanover,N.H.Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.Which of the following is closest in meaning to the word"build"in the first sentence of thesecond paragraph?A:Construct.B:Establish.C:Create.D:Expand.
考题
单选题—The water changes into thick ice covering rivers and lakes in winter in Harbin.—_____ in Urumqi and children go skating on it then.A
So is itB
So it doesC
So it isD
So does it
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 temperatureB
Chilled water system return temperatureC
Compressor discharge temperatureD
Compressor suction pressure
考题
单选题The scientists are not sure_______.A
how long the ice age lastedB
where ice sheets melted during the ice ageC
what caused the temperature changesD
what the earth is made up of
考题
单选题（）can not cause oil flow from water outlet of self-cleaning separator.A
Oil temperature too highB
Diameter of gravity disc too largeC
Oil temperature too lowD
High level tank out of water
考题
单选题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 dischargeB
expansion tank outletC
cooling water heat exchangerD
outlet engine jacket water outlet
考题
单选题In a diesel engine jacket water cooler, with seawater cooling the fresh water, the（）A
sea water temperature must never be warmer than 40℃B
jacket water pressure should always be greater than the sea water pressureC
jacket water temperature must always be less than 60℃D
jacket water pressure must always be less than the sea water pressure
考题
单选题The second stage feed-water temperature and shell absolute pressure in a multistage, flash type, distilling plant is （）A
higher than the first stage feed-water temperature and absolute shell pressureB
lower than the first stage feed-water temperature and absolute shell pressureC
the same as the first stage feed-water temperature and absolute shell pressureD
not related to the feed-water temperature and absolute shell pressure
考题
单选题The amount of heat released by steam when it changes to water at the same temperature is called（）.A
latent heat of condensationB
latent heat of vaporizationC
latent heat of saturationD
sensible heat of condensation
考题
单选题If the compressor-discharge temperature is higher than the receiver temperature（）A
increase the amount of cooling water to the condenserB
decrease the amount of cooling water to the condenserC
add more refrigerant to the systemD
remove some of the refrigerant from the system
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