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Soil is the surface layer of the Earth that nourishes and supports the growth of rooted plants.
A: accepts
B:arranges
C:feeds
D:shelters
B:arranges
C:feeds
D:shelters
参考答案
参考解析
解析：本句意思：土壤是滋养和支撑根茎植物生长的地球表层。nourish滋养。feed喂养； accept接受；arrange安排；shelter避难。
更多 “Soil is the surface layer of the Earth that nourishes and supports the growth of rooted plants.A: accepts B:arranges C:feeds D:shelters” 相关考题
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根据文章，回答 67～70 问题DHave you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do you think caused this change in colour? It is soil that has been washed into the river from the riverbank or from t}le nearby fields．Components of SoftSoil is made up of a number of layers(层)，each having its own distinctive colour and texture．The upper layer is known as the litter．It acts like a blanket．limiting temperature changes and reducing water loss．The topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter called humus(腐殖质)，which is black and gives the topsoil its dark colour．This layer is usually rich in nutrients，oxygen，and water．Below the topsoil is the subsoil，a layer that contains more stones mixed with only small amounts of organic matter．This layer is lighter in colour because of the lack of humus．Beneath the soil lies a layer of bedrock．Soil forms from the bottom up．Over time bedrock is attacked by rain, wind，frost, and snow．It is gradually broken down into smaller particles in a process called weathering．Plants begin to grow，and rotten materials enrich the topsoil．Most of the soil in Eastern Canada．for example．Was formed from weathered rock that was exposed when the ice disappeared l2．000 years ag0．Water Beneath the SoilSurface water collects and flows above the ground in lakes．ponds．and rivers．Once in the soil or rock，it is called groundwater．Gravity pulls groundwater through the soil in a process called percolation(渗透)．Eventually the water reaches a layer called the water table．Under this is bedrock through which water cannot percolate．As water percolates downward，it dissolves organic matter and minerals from the soil and carries them to deeper layers．This causes a serious problem because plants require these nutrients for growth.Soil pHSoil can be acidic．neutral．or basic．The pH of the soil is determined by the nature of the rock．from which it was formed．and by the nature of t}le plants that grow and rot in it．The acidity of rain and snow can lower the pH of the groundwater that enters the soil．By burning fossil fuels such as coal，oil and gasoline，humans have been contributing to higher levels of acidity in many soils．When fossil fuels are burned．gases are released into the air and then fall back to earth as acid rain．Acid soil increases出e problem of carrying nutrients to lower soil levels．As nutrients are removed，soil is less fertile．Plants grow more slowly in acidic soil，and also become easily attacked by diseases．第12题：The layer of soil that provides necessary nutrients for plant growth is called．A．1itterB．topsoilC．humusD．subsoil
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According to the text．which of the following is NOT true?A．Soil forms from weathered rock on the earth surface．B．The deeper layer of soil is darker in colour than t}le surface soil．C．Air pollution is partially responsible for acid soil．D．Groundwater tends to carry away nutrients for plant growth．
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____ is covered with heavy snow.
A.The earth's surfaceB.The surface of earthC.The surface earthD.The earth surface
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A.thatB.asC.whichD. then
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According to the text. which of the following is NOT true?A. Soil forms from weathered rock on the earth surface.B. The deeper layer of soil is darker in colour than the surface soil.C. Air pollution is partially responsible for acid soil.D. Groundwater tends to carry away nutrients for plant growth.
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Geothermal(地热)Energy
1 Since heat naturally moves from hotter regions to cooler ones, the heat from the earth's center flows outwards towards the surface. In this way, it transfers to the next layer of rock. If the temperature is high enough, some of this rock melts and forms magma(岩浆). The magma ascends in its turn towards the earth's surface. It often remains well below the earth's surface, creating vast areas of hot rock. In such regions, there are deep cracks, which allow rainwater to descend underground. Some of the heated rainwater travels back up to the earth's surface where it will appear as a hot spring. However, if this ascending hot water reaches a layer of impermeable(不可渗透的)rock, it remains trapped, forming a geothermal reservoir. If geothermal reservoirs are close enough to the surface, they can be reached by drilling wells. Hot water and steam shoot up the wells naturally, and can be used to produce electricity in geothermal power plants.
2.A few geothermal power plants depend on dry-stem reservoirs which produce steam but little or no water. In these cases, the steam is piped up directly to provide the power to spin a turbine generator. The first geothermal power plant, constructed at Lardarello in Italy, was of this type, and is still producing electricity today.
3.Most currently operating geothermal power plants are either "flash" steam plants or binary(双重的)plants. Flash plants produce mainly hot water ranging in temperature from 300° to 700°Fahrenheit. This water is passed through one or two separators where released from the pressure of the underground reservoir, it "flashes" or boils into steam Again, the force of this steam provides the energy to spin the turbine and produce electricity. The geothermal water and steam are then reinjected directly back down into the earth to maintain the volume and pressure of the reservoir. Gradually they will be reheated and can then be used again.
4.A reservoir with temperatures below 300° Fahrenheit is not hot enough to flash steam but it can still be used to generate electricity in binary fluid. The steam from this is used to power the turbines. As in the flash steam plant, the geothermal water is recycled back into the reservoir.
文章(23~30)
Paragraph1_____A.Dry steam plants
B.Binary plants
C.Origin of geothermal energy
D.Generation of electricity
E.Flash steam plants
F.Recyclable water and steam
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共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.According to the passage,"weight"should be understood in the sense thatA:it is fixed if it is outside the earth's gravitational puliB:it decreases four times when it is 4,000 miles from the earth's centerC:it varies with the change of the gravitational attraction between two objectsD:things increase in amount as they are closer to the earth's surface
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共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.How much would four pounds of tea weigh if it was taken 4,000 miles out from the surface of the earth?A:1 pound. B:2 pounds. C:3 pounds. D:4 pounds.
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共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.We do not feel the gravitational pull of a packet of butter becauseA:it is too small to have a gravitational pull of its ownB:its puil is so small that we tend to ignore itC:its pui1 disappears in the presence of the earth's gravitationD:it tends to melt and loses its gravitational puli
考题
共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.We find it hard to break free from ideas connected with living on the earth because______.A:it demands too great an effort for us to do soB:we are too familiar with the way things are to question the ideasC:we have proved that those ideas are correctD:we are so sure of ourselves that we never doubt anything on the earth
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Which three are benefits of IS - IS over OSPF?（）A、supports route tagsB、supports more routers in an areaC、does not require Hello packets to establish neighbor relationshipsD、produces fewer link state advertisements for a given networkE、supports network layer protocols other than IPF、requires fewer neighbor relationships in a broadcast multiaccess network
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Which of the following are key characteristics of PPP (Choose three.)（）。A、can be used over analog circuitsB、maps Layer 2 to Layer 3 addressC、encapsulates several routed protocolsD、supports IP onlyE、provides error correction
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Which of the following are key characteristics of PPP?（）A、can be used over analog circuitsB、maps Layer 2 to Layer 3 addressC、encapsulates several routed protocolsD、supports IP onlyE、provides error correction
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单选题Ice blink is（）.A
the dark appearance of the underside of a cloud layer due to reflection of a surface of open waterB
the soft light appearance on the underside of a cloud layer due to reflection from a surface of open waterC
the yellowish-white glare on the underside of a cloud layerD
water sky
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单选题Advection fog is most commonly caused by（）.A
air being warmed above the dew pointB
saturation of cold air by rainC
a rapid cooling of the air near the surface of the Earth at nightD
warm moist air being blown over a colder surface
考题
单选题A plane perpendicular to the polar axis will never form what line on the Earth’s surface? （）A
Great circleB
EquatorC
Small circleD
Meridian
考题
单选题_____ from space, our earth, with water covering 70% of its surface, appears as a “blue planet”.A
SeeingB
To be seenC
SeenD
Having seen
考题
单选题（）means the curve on the earth’s surface which cuts all the meridians at the same angle.A
Great CircleB
Position LineC
Rhumb lineD
True Bearing
考题
单选题Without the sun’s light _____ the earth’s surface, it would be so cold that life could not exist on the earth.A
warmsB
warmedC
warmingD
to warm
考题
单选题_____ most of the earth's surface is covered by water, fresh water is very rare and precious.A
AsB
OnceC
IfD
Although
考题
单选题_____from space, our earth, with water covering 70% of its surface, appears as a blue planet.A
SeeingB
To be seenC
SeenD
Having seen
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