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水闸、涵洞、溢洪道等过水建筑物的平面图，应使水流方向如何布置视图？ How to layout plans of water gate and other structures ？ One needs to make the water flow from ？
A．从后往前from rear to front
B．从前往后from front to rear
C．从左到右from left to right
D．从右到左from right to left
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更多 “水闸、涵洞、溢洪道等过水建筑物的平面图，应使水流方向如何布置视图？ How to layout plans of water gate and other structures ？ One needs to make the water flow from ？A．从后往前from rear to frontB．从前往后from front to rearC．从左到右from left to rightD．从右到左from right to left” 相关考题
考题
Water is the __46___ of all the things we eat and drink . Not many people understand this but __47____ quite true . The human body can go without ___48___ for a long time . We’ve got many examples for this . Yet two __49___ three days without water can usually make people __50____ . Man can’t live __51____ water .Many people don’t understand how ___52__ water the human body needs __53___ work well , and many people , especially young people , do not drink enough , ___54__ in very hot weather . Our body has mostly water , about 65% to 75% . That is to say about two thirds of our body is water . When we do sports , some of the water will get away from our body . __55 _ we don’t drink some water , we won’t have enough water． And if we don’t have enough water , we’ll feel tired and many of us will get ill . So you know how important water is to us .46.___________( )46. A. importantB. most importantC. more importantD. different
考题
EThe need to feed a growing population is putting much pressure on the world’s supply of water. With 97% of the world’s water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. Although the idea of a water shortage（短缺）seems strange to someone fortunate enough to live in a high rainfull country, many of the world’s agricultural industries experience constant water shortages.Although dams can be built to store water for agricultural use in dry areas and dry seaons, the costs of water redistribution(重新分配)are very high. Notonly is there the cost of the engineering itself, but there is also an environmental cost to be considered. Where valleys(山谷)are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water many flow easily through pipes to fields,but it cannot be transported from one side of the world to the other. Each country must therefore rely on the management of its own water to supply its farming requirements.This is particularly troubling ro countries with agricultural industries in areas dependent on irrigation（灌溉）. In Texas, farmers’ overuse of irrigation water be resulted in a 25% redcution of the water stores. In the Central Valley area of south eastern USA, a huge water engineering project provided water for farming in dry vallege, but much of the water use has been poorly managed.Saudi Arabia’s attempts to grow wheat in desert areas have been the pumping of huge quantities of irrigation water from underground reserves. Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping will see them run dry.72. From the first two paragraphs we learnt that _______.A.much of the world’s water is available for useB.people in high rainfll countries feel luckyC.the costs of water redistribution should be consideredD.water can be easily carried through pipes across the world
考题
— I wonder ________ you’ll water this kind of flower .——Every other day.A. how often B. how longC. how soonD. how much
考题
BThe world is not only hungry，it is also thirsty for water． this may seem strange to you，since nearly 75% of the earth is covered with water． But about 97% of this water is sea water．Man can only drink and use the other 3% fresh water that comes from rivers，lakes，under-ground and other places． And we cannot even use all of that，because some of this fresh water has been made dirty．At the moment，this small amount(数量) of fresh water is still enough for us． However，our need for water is getting greater and greater． Only if we take steps to solve this problem now，we can get away from a serious world water shortage later on． The people of the world cannot have an enjoyable life without enough clean water．On one hand we should stop wasting this little water of ours，on the other hand we should find ways to reuse it，but this has not been done widely．Today，in most large cities，water is used only once and it then returns to the sea or runs into underground places．lf we can make it clean again，it can be used once more just as if it were fresh from a spring．But even if large cities reuse its water，we still would not have enough in the future． Where．could we turn to next for water? To the ocean! How can we do to make use of this great a-mount of sea water? We can take the salt from the water to make it fresh．So if we take all these steps，we'll be in no danger of drying up!( )26． Why does the writer say that the world is thirsty for water?A． The amount of fresh water is really very small．B． The people of the world waste too much water．C． The people of the world have to drink a lot of water every day．D． There are too many people in the world needing water．
考题
29． The writer thinks that people in large cities should __________ ．A． stop the used water from getting into undergroundB． only use the water from the riversC． make their used water clean againD． use as much sea water as possible
考题
30． In order to solve the problem of water shortage，we' have to________．a． make use of sea water on the earthb． save as much fresh water as possiblec． reuse the water from large citiesd． stop people from，using watere． only use the 3% of the water on the earthA．a and eB．a，b and cC．b，c and dD．a，b and d
考题
One of the reasons that causes oil flowed from sludge outlet of a self-cleaning purifier isA.seal water supply be cut offB.make-up water supply be cut offC.oil outlet valve closed or not open sufficientlyD.the flow rate of oil is too much
考题
One of the most common causes of reduction gear failure is gear wear caused by scoring as a result ofA.surface fatigue of the gearsB.an inadequate lube oil filmC.plastic flow of the gearsD.fretting corrosion from water
考题
What do we know about golf from the passage?A． It is popular in Portugal and SpainB． It causes water shortages around the worldC． It pollutes the earth with chemicals and wastesD． It needs water and electricity to keep its courses green
考题
According to the last paragraph, the fourth way is "of a different kind" because（ ）[A] the first three ways can increase the water supply, while the fourth one can't[B] the first three ways can make a better use of water, while the fourth one can't[C] the first three ways is technology-based, while the fourth one is market-based[D] the first three ways can't balance the supply and demand of water, while the fourth one can
考题
When is the density of the water required to be logged in the logbook of a ship?A.Any time the vessel moves from water of one density into waters of a different densityB.Prior to getting underway when the vessel is floating in fresh or brackish waterC.Only when the vessel moves from fresh water into salt waterD.The density of the water is not required to be logged in the unofficial logbook
考题
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
考题
Before loading bulk grain, bilge wells must be covered to ______.A.add strength to the bilge well strainerB.permit rapid flow of water to the bilge wellsC.prevent cargo sifting into the bilge wellsD.prevent oil, water, or other liquid from reaching the cargo
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.
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
The purpose of mentioning the Weddell Sea is___________.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
The water we drink and use is running short in the world.We all have to learn how to stop wasting our limited water.One of the steps we should take is to find ways of reusing it.Experiments have already been done in this field.
Today in most large cities,fresh water is used only once,then it runs into waste system.But it is possible to pipe the used water to a purifying factory.There it can be filtered and treated with chemicals so that it can be used again,just as it were fresh from a spring.
But even if every large city purified and reused its water,we still would not have enough.Then we could turn to the oceans.All we’d have to do to make use of the seawater on earth is to get rid of the salt.This process is called desalinization,and it is already in use in many parts of the world.
The way to stop wasting our limited water is to________.A.do experiments with water
B.purify the used water and reuse it
C.use fresh water once again
D.make use of seawater
考题
Some villagers were going to celebrate an important wine festival（酒宴）in a few days′time,so?they borrowed a huge barrel from the nearest town,put it in the village square,and decided that each?of them should empty a bottle of the best wine he had into it,so that there should be plenty at the?feast（宴会）.
One of the villagers thought he would be very clever."If I pour a bottle of water in,instead of?wine,no one will notice it,"he said to himself,"because there will be so much excellent wine in the?barrel that?the water will be lost in it."
The night of the feast arrived.Everybody gathered in the village square with their bowls and?their glasses for the wine.The tap（塞子）on the barrel was opened,but what came out was pure?water.Everyone in the village had had the same idea.
The underlined sentence"the water will be lost in it"can be considered as__________.A.the water would be gone in the barrel
B.the water couldn't be found in the wine
C.the water would flow through the barrel into the ground
D.the water would be mixed up with the wine
考题
单选题According to the Code of Federal Regulations，on vessels other than river ferryboats and river vessels，how are periodic lifeboat weight tests required to be conducted?（）A
The lifeboat is lowered to near the water，loaded with the allowed capacity，lowered into the water until afloat，then released from the fallsB
The lifeboat is loaded with the allowed capacity，lowered into the water until afloat，then released from the fallsC
The lifeboat is lowered into the water until afloat，loaded with the allowed capacity，then released from the fallsD
The lifeboat is lowered to near the water，loaded with the allowed capacity，then released from the falls
考题
单选题Before loading bulk grain，bilge wells must be covered to（）.A
add strength to the bilge well strainerB
permit rapid flow of water to the bilge wellsC
prevent cargo sifting into the bilge wellsD
prevent oil，water，or other liquid from reaching the cargo
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One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）A
seal water supply be cut offB
make up water supply be cut offC
oil outlet valve closed or not open sufficientlyD
the flow rate of oily water is too much
考题
单选题One of the reasons that causes oil flowed from sludge outlet of a self-cleaning purifier is （）A
seal water supply be cut offB
make-up water supply be cut offC
oil outlet valve closed or not open sufficientlyD
the flow rate of oil is too much
考题
单选题When is the density of the water required to be logged in the logbook of a ship?（）A
Any time the vessel moves from water of one density into waters of a different densityB
Prior to getting underway when the vessel is floating in fresh or brackish waterC
Only when the vessel moves from fresh water into salt waterD
The density of the water is not required to be logged in the unofficial logbook
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One of the causes of ocean currents is density differences in the water. This is true because （）.A
in an area of high density the water's surface is lower than in an area of low densityB
surface water flows from an area of high density to one of low densityC
the lesser the density gradient the freer the water is to moveD
it is the density differences that cause the currents to stay in the troughs
考题
单选题One function of the thermal expansion valve is to（）A
act as a pilot from the solenoid valveB
regulate the amount of refrigerant flow to the coilC
regulate the water flowD
turn the compressor off and on
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