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
30． In order to solve the problem of water shortage，we' have to________．
a． make use of sea water on the earth
b． save as much fresh water as possible
c． reuse the water from large cities
d． stop people from，using water
e． only use the 3% of the water on the earth
A．a and e
B．a，b and c
C．b，c and d
D．a，b and d
相关考题：
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
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
Which of the following is true?A.The water in Texas have been reduced by 75%.B.Most industries in the world suffer from water shortagers.C.The underground water in Saudi Arabia might run out in 50 years.D.Good management of water use resulted from the project in the Central Valley.
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．
27． From the passage we know that fresh water doesn't come from________ ．A．riversB．lakesC．undergroundD．the sea
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
In Leon Nacson’s view, air and water are our Number One priorities for the following reasons except ().A、he cannot understand why people are polluting air and waterB、there will definitely be no fresh air and clean water for future generationsC、we would run out of air and water if we didn’t stop polluting themD、air and water polluting are the current and futu
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
After being launched from a vessel, totally enclosed survival craft which have been afloat over a long period require ______.A.frequent opening of hatches to permit entry of fresh airB.regular checks of bilge levelsC.use of ear plugs to dampen engine noiseD.frequent flushing of the water spray system with fresh water
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 ofhigh 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 salinityB．to point out the location of deep watersC．to make a comparison between hot-water salinity and cold-water salinityD．to show that the water in the Weddell Sea varies in salinity from place to place
The purpose of mentioning the Weddell Sea is___________.A.to give an example of cold-water salinityB.to point out the location of deep watersC.to make a comparison between hot-water salinity and cold-water salinityD.to show that the water in the Weddell Sea varies in salinity from place to place
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
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.
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._________52A:buy B:treatC:haveD:use
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.The word"fraction"in the second paragraph means________.A:a large areaB:a very small amountC:an important systemD:a major source of information
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.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
共用题干Where Did the Earth's Water Come From?Earth is located within the"snow line"of the solar system,the region closest to the Sun where H2 0 is primarily in liquid or gaseous form,if at all.______(46)The snow line phenomena is reflected in the water content of planets like Mercury,Venus,and Mars. Water is absent on Mercury.On Venus,H2O only exists as a trace element in the atmosphere.Mars only has a thin veneer of ice in its polar regions.In general,water is rare within the snow line.Why does Earth have so much water relative to the other inner planets?71%of the surface is covered in the oceans,more than half of which is deeper than 3,000 meters,with an approximate total volume of 1.3 billion cu km.______(47)There are various theories as to where all the Earth's water came from,but several theories have fared better than the others.______(48)When the Earth was in the process of forming,with a radius just 40%smaller than at present,it would have had enough gravity to hold on to a tenuous atmosphere with water vapor. The first water vapor on the planet would have come from the planet's internals,where volatile(low weight)chemicals would have a tendency to float to the top,and heavy chemicals(iron and nickel)would sink.Though the first of Earth's water came about through volcanism,this alone probably didn't produce enough to form stable pools on the surface.______(49)Comparing the isotope ratios of water on Earth and water from comets and asteroids has revealed that the majority of the Earth's water comes from asteroids.Throughout its history,Earth's water has increased in volume due to biological processes. In the early seas of Earth,hydrogen sulfide would have been in great supply,which,when reacted with carbon dioxide from the atmosphere during photosynthesis in sulfide-reducing bacteria,would have produced hydrogen,sulfur,and water.______(50)________（49）A: More water was added to the planet during several hypothesized large impacts from asteroids from the outer asteroid belt.B:We know that the oceans existed as early as 100 million years after the formation of the Earth.C:Still,the oceans only make up 0.023%of the Earth's total mass.D:Astronomers say Earth s water may have come from space.E:The snow line is located in the outerasteroid belt,between the orbits of Mars and Jupiter. F: Many geologists believe that the majority of Earth's water generated through this process.
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 waterB.purify the used water and reuse itC.use fresh water once againD.make use of seawater
The best title for the passage is“_______”.A.How to Reuse WaterB.Two Solutions to the Problem of Water ShortageC.Stop Wasting Our Limited WaterD.How to Make Use of Seawater
There wouldn’t be enough water for us if we didn’t_________.A.turn to the oceans for more waterB.reuse used water and make use of seawaterC.desalt seawaterD.take steps to reuse all water on earth
单选题We use （） to distill fresh water from sea water.AengineBsea water pumpCcylinder coolerDfresh water generator
单选题You are proceeding to a distress site and expect large numbers of people in the water. Which statement is TRUE?（）AYou should stop to windward of the survivors in the water and only use the ship's boats to recover the survivorsBIf the survivors are in inflatable rafts you should approach from windward to create a lee for the survivorsCAn inflatable liferaft secured alongside can be an effective boarding station for transfer of survivors from the boatsDSurvivors in the water should never be permitted alongside due to the possibility of injury from the vessel
单选题An excessive amount of water is prevented from entering a vessel using a water lubricated stern tube bearing by the use of the （）.Apropeller hubBlignum vitaeCshaft packingDlabyrinth seal
单选题When is the density of the water required to be logged in the logbook of a ship?（）AAny time the vessel moves from water of one density into waters of a different densityBPrior to getting underway when the vessel is floating in fresh or brackish waterCOnly when the vessel moves from fresh water into salt waterDThe density of the water is not required to be logged in the unofficial logbook
单选题Which statement concerning the collection of fresh water is FALSE?（）AFresh water may be obtained from fishBlifeboat covers or canopies should be washed with rain before drinking water is collectedCFresh water may be collected from condensation inside the life-raftDFreshwater cannot be produced from standing seawater
问答题Practice 5 Water is essential for life. Yet many millions of people around the world face water shortages. Many millions of children die every year from water-borne diseases. And drought regularly afflicts some of the world’s poorest countries. The world needs to respond much better. We need to increase water efficiency, especially in agriculture. We need to free women and girls from the daily chore of hauling water. We must involve leaders of countries in decision-making on water management. We need to make sanitation a priority. This is where progress is lagging most. And we must show that water resources need not be a source of conflict. Instead, they can be a catalyst for cooperation. Significant gains have been made. But a major effort is still required. Our goal is to meet the internationally agreed targets for water and sanitation by 2015, and to build the foundation for further progress in the years beyond. This is an urgent matter of human development, and human dignity. Together, we can provide safe, clean water to the entire world’s people. The world’s water resources are our lifeline for survival, and [or sustainable development in the 21st century. Together, we must manage them better.
单选题The fresh water generator produces fresh water （）.Aby cooling sea waterBby heating sea waterCby evaporation of sea waterDby purifying sea water