Have 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 Soft
Soil 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 Soil
Surface 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 pH
Soil 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.
1.The layer of soil that provides necessary nutrients for plant growth is called.
A.1itter B.topsoil C.humus D.subsoil
2.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.
3.We can infer from the passage that the water table lies________.
A.between the topsoil layer and the subsoil layer
B.in the subsoil layer above bedrock
C.between the subsoil layer and bedrock
D.in the bedrock layer beneath the subsoil
4.The underlined word “dissolve” is used to express the idea that organic matter and minerals from soil are ________.
A.rushed away into the river
B.cleaned and purified by water
C.destroyed and carried away by water
D.mixed with water and become part of it
高三英语阅读理解困难题
Have 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 Soft
Soil 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 Soil
Surface 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 pH
Soil 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.
1.The layer of soil that provides necessary nutrients for plant growth is called.
A.1itter B.topsoil C.humus D.subsoil
2.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.
3.We can infer from the passage that the water table lies________.
A.between the topsoil layer and the subsoil layer
B.in the subsoil layer above bedrock
C.between the subsoil layer and bedrock
D.in the bedrock layer beneath the subsoil
4.The underlined word “dissolve” is used to express the idea that organic matter and minerals from soil are ________.
A.rushed away into the river
B.cleaned and purified by water
C.destroyed and carried away by water
D.mixed with water and become part of it
高三英语阅读理解困难题查看答案及解析
"Have you ever been out on a boat and felt it lifted up by a wave? Or have you jumped in the water and felt the rush of energy as waves came over you.?" asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh. "There is certainly a lot of energy in waves," he said. Scientists are working to use that energy to make electricity. Most waves are created when winds blow across the ocean. "The wind starts out by making little ripples (涟漪), but if they keep on blowing, those ripples get bigger and bigger and turn into waves," Taylor said. "Waves are one of nature's ways of picking up energy and then sending it off on a journey." When waves come toward the shore, people can set up dams to block the water and send it through a large wheel called a turbine (涡轮机). The turbine can then power an electrical generator to produce electricity.
"The resource is huge," said Janet Swain of the World Watch Institute. "We will never run out of wave power." Besides, wave energy does not create the same pollution as other energy sources, such as oil or coal. Oceans cover three-quarters of the Earth's surface---that would make wave power seem ideal for creating energy throughout the world, though there are some weak points yet to overcome.
Swain said that wave power still costs too much money. She also said that its effects on sea animals are still unknown. What is more, wave power could affect fishing and boat traffic. Traditional sources of energy like oil and gas may someday run out. "Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is rising rapidly throughout the world," Swain said. In the future when you turn on a light, an ocean wave could be providing the electricity!
1.The underlined phrase "picking up" is closest in meaning to ______.
A. starting again B. speeding up
C. improving D. gathering
2.We can make better use of wave energy if we ______.
A. shorten its journey to thousands of homes
B. build more small power stations on the oceans
C. reduce the cost of turning it into electric power
D. quicken the steps of producing electricity
3.It can be inferred that some day we might not worry about ______.
A. our power supply B. our boat traffic
C. air pollution D. our supply of sea fish
高三英语阅读理解中等难度题查看答案及解析
"Have you ever been out on a boat and felt it lifted up by a wave? Or have you jumped in the water and felt the rush of energy as waves came over you.'?" asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh. "There is certainly a lot of energy in waves," he said.
Scientists are working to use that energy to make electricity. Most waves are created when winds blow across the ocean. "The wind starts out by making little ripples (涟漪), but if they keep on blowing, those ripples get bigger and bigger and turn into waves," Taylor said. "Waves are one of nature's ways of picking up energy and then sending it off on a journey."
When waves come toward the shore, people can set up dams to block the water and send it through a large wheel called a turbine (涡轮机). The turbine can then power an electrical generator to produce electricity.
"The resource is huge," said Janet Swain of the Worldwatch Institute. "We will never run out of wave power." Besides, wave energy does not create the same pollution as other energy sources, such as oil or coal. Oceans cover three-quarters of the Earth's surface - that would make wave power seem ideal for creating energy throughout the world, though there are some weak points yet to overcome.
Swain said that wave power still costs too much money. She also said that its effects on sea animals are still unknown. What is more, wave power could affect fishing and boat traffic.
Traditional sources of energy like oil and gas may someday run out. "Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is rising rapidly throughout the world," Swain said. In the future when you turn on a light, an ocean wave could be providing the electricity!
1.The writer uses the two questions at the beginning of the passage to _______.
A. test the readers' knowledge about waves
B. draw the readers' attention to the topic
C. show Jamie Taylor's importance
D. invite the readers to answer them
2.The underlined phrase "picking up" (paragraph 2) is closest in meaning to _______.
A. starting again
B. speeding up
C. gathering
D. improving
3.We can make better use of wave energy if we _______.
A. shorten its journey to thousands of homes
B. build more small power stations on the oceans
C. reduce the cost of turning it into electric power
D. quicken the steps of producing electricity
4.It can be inferred that some day we might not worry about ________.
A. air pollution
B. our boat traffic
C. our power supply
D. our supply of sea fish
高三英语阅读理解中等难度题查看答案及解析
B
“Have you ever been out on a boat and felt it lifted up by a wave? Or have you jumped in the water and felt the rush of energy as waves came over you?” asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh. “There is certainly a lot of energy in waves,” he said. Scientists are working to use that energy to make electricity. Most waves are created when winds blow across the ocean. “The wind starts out by making little ripples(涟漪), but if they keep on blowing, those ripples get bigger and bigger and turn into waves,” Taylor said. “Waves are one of nature’s ways of picking up energy and then sending it off on a journey.” When waves come toward the shore, people can set up dams to block the water and send it through a large wheel called a turbine(涡轮机). The turbine can then power an electrical generator to produce electricity.
“The resource is huge,” said Janet Swain of the World Watch Institute. “We will never run out of wave power.” Besides, wave energy does not create the same pollution as other energy sources, such as oil or coal. Oceans cover three quarters of the Earth’s surface—that would make wave power seem ideal for creating energy throughout the world, though there are some weak points yet to overcome.
Swain said that wave power still costs too much money. She also said that its effects on sea animals are still unknown. What is more, wave power could affect fishing and boat traffic. Traditional sources of energy like oil and gas may someday run out. “Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is rising rapidly throughout the world,” Swain said. In the future when you turn on a light, an ocean wave could be providing the electricity!
1.The writer uses the two questions at the beginning of the passage to .
A. test the readers’ knowledge about waves
B. draw the readers’ attention to the topic
C. show Jamie Taylor’s importance
D. invite the readers to answer them
2.The underlined phrase “picking up” is closest in meaning to .
A. starting again B. speeding up
C. improving D. gathering
3.We can make better use of wave energy if we .
A. shorten its journey to thousands of homes
B. build more small power stations on the oceans
C. reduce the cost of turning it into electric power
D. quicken the steps of producing electricity
4.It can be inferred that someday we might not worry about .
A. our power supply
B. our boat traffic
C. air pollution
D. our supply of sea fish
高三英语阅读理解中等难度题查看答案及解析
Have you ever noticed how the way you feel about yourself sometimes depends on whether or not you get confirmation of your value from others?
I have______a lot about nurturing a positive identity of love and appreciation from the man who taught me to train dogs.
First, he started out by ______his dogs with love and respect, and by showing them an infinite amount of______as they were learning.
Then, the______thing he did was a true stroke of genius. He would cut a small piece of______for each dog. He would place it in the dog's sleeping area, for him to______each night. He would also take this carpet during the______and set it down in various locations, and sit the dog on the carpet, as he______the dog for being good.
Next, Frank would teach the dog to______the carpet himself, and carry it to_____ they were going. The dog would then set the carpet down when they______, with Frank all of the time praising him. Now Frank said, "The dog begins to feel that he truly______in every place he travels to, and no matter where he goes, he______my love and appreciation. "
If this strategy______so brilliantly with dogs, would it not work just______with human beings?
1.A.learned B.accumulated C.improved D.distinguished
2.A.pleasing B.treating C.surrounding D.chasing
3.A.sympathy B.comfort C.patience D.honor
4.A.first B.last C.next D.least
5.A.cloth B.meat C.area D.carpet
6.A.lie on B.hide in C.stand beside D.play with
7.A.morning B.afternoon C.evening D.day
8.A.blamed B.encouraged C.praised D.accompanied
9.A.carry with B.care for C.cut up D.pick up
10.A.wherever B.whenever C.however D.whatever
11.A.ran B.stopped C.stood D.turned
12.A.participated B.breaks C.belongs D.corresponds
13.A.receives B.expects C.ignores D.takes
14.A.works B.goes C.agrees D.applies
15.A.as possible B.as well C.better than D.still less
高三英语完形填空困难题查看答案及解析
When you are sitting in the car, do you ever notice the drivers looking over their shoulders or side to side in the car? Well, they are doing this to check their blind spots! Blind spots take driving extremely difficult and increase the potential for car accidents.
Fourteen-year-old Alaina Gassler from Pennsylvania noticed her mother struggling with blind spots while driving their family car. So she came up with an ingenious solution that won the first place and $25,000 in the Broadcom Masters Competition.
Blind spots are the areas around the car that cannot be directly observed by the driver. There are two kinds of blind spots---on the back of the car that cannot be seen with mirrors, and blind spots at the front of the car as well.
When a driver is changing lanes, he has to look over his shoulder through the side windows to make sure that there is no vehicle in the blind spot. This invisible area is big enough to hide a car!
The other blind spot is created in the front by the A-pillar(柱子)---the material on either side on the windshield(挡风玻璃)that holds the glass and forms the frame of the car. In some cars, this pillar can be quite thick. Usually, people or cyclists can be hidden by this pillar.
Alaina's design was to get rid of the blind spot created by the front A-pillar of the car, the one that helps hold up the windshield.
She put a camera on the outside passenger side of the car which then sent the photos to a projector above the drivers' head. Then, she covered the inside of the pillar in reflective fabric onto which the image was projected. Basically, her device made the pillar "see through" and removed the blind spot on that side of the car.
Alnina's solution is very creative and could be improved by using LCD displays that will make it easier to see during day time as well.
1.What can be learned about blind spots during driving?
A.They call for careful driving. B.They make driving thrilling.
C.They are many in kinds. D.They can't be get rid of.
2.Which of the following can replace the underlined word "ingenious" in paragraph 2?
A.interesting B.creative
C.inspiring D.invisible
3.How did Alaina solve the problem?
A.By improving the A-pillar. B.By using a mirror on the outside of the A-pillar.
C.By relying on LCD displays. D.By using a camera to capture images.
4.What's the best title for the text?
A.An Introduction to Blind Spots B.A Warning About the Road Safety
C.A Teen's Creative Solution to Blind Spots D.Scientific Research on Blind Spots
高三英语阅读理解中等难度题查看答案及解析
If you swim in a river or lake, be sure to investigate is below the water surface. Often there are rocks or branched hidden in the water.
A. what B. who
C. that D. whoever
高三英语单项填空中等难度题查看答案及解析
If you swim in a river or lake, be sure to investigate is below the water surface. Often there are rocks or branched hidden in the water.
A. what B. who C. that D. whoever
高三英语单项填空中等难度题查看答案及解析
Have you ever noticed tiny raised areas on the branches of a tree? These may have been insects. These small insects feed on tree sap (汁液). Insects on urban trees are notably more abundant than those on rural trees. As a result, urban trees suffer from heavy infestations (害虫横行), and are often unhealthy or die. To protect and restore urban trees’ health, we need to determine the factors that make these tree pests more successful in urban habitats.
Living organisms interact closely with their environment. The warmer, more drought-stressed trees harbor more successful pests than cooler, less drought-stressed trees. As cities and natural habitats become hotter and drier, damaging insects will become more abundant on urban trees.
Trees within urban forests are valuable economically and for the environmental sustainability (可持续性) of the region. More than half of the world’s population lives in cities. Across the globe, people are moving into cities at a faster rate than ever. Rapid growth may turn cities into places with harder conditions. Although cities are primarily made of buildings, roads, parking lots, and vehicles, there are still plants in them. The trees within a city are referred to as the urban forest. Urban forests offer very big benefits to human and environmental health. They improve air and water quality, provide habitat for wildlife, cool down temperatures and beautify our environment. They make cities livable.
However, being a city tree is not easy. Heat released by human activities is trapped in cities. As a result, temperatures in urban areas are often warmer than their surrounding rural areas. We call this urban warming or the urban heat island effect. Urban habitats are mostly made of surfaces of asphalt (沥青) and concrete. These surfaces reduce the amount of rainwater that reaches tree roots. As a result, urban forests may suffer, which can negatively affect people and the environment.
What can we do to restore urban forests? Regular irrigation when possible may help keep pest populations under control. Planting tree species that are suitable to handle heat and drought stress would also reduce the occurrence of insect pest outbreaks.
1.What makes tree pests more successful in the city than in rural areas?
A.The warmer and rainy habitat.
B.The hotter and drier habitat.
C.The cooler and drier habitat.
D.The hotter and rainy habitat.
2.Urban forests make cities livable by .
A.providing people enough clean water
B.improving the living environment
C.offering people economic benefits
D.lowering the temperatures
3.According to the text, what results in the city trees’ suffering?
A.Natural disasters.
B.Invisible forces.
C.Human activities.
D.Natural evolution.
4.What would be the best title for the text?
A.The Importance of the Urban Trees
B.How to Protect the Urban Trees
C.Urban Trees Are in Great Danger
D.Let’s Act for the Protection of Urban Trees
高三英语阅读理解中等难度题查看答案及解析
Have you ever noticed tiny raised areas on the branches of a tree? These may have been insects. These small insects feed on tree sap (汁液). Insects on urban trees are notably more abundant than those on rural trees. As a result, urban trees suffer from heavy infestations (害虫横行), and are often unhealthy or die. To protect and restore urban trees’ health, we need to determine the factors that make these tree pests more successful in urban habitats.
Living organisms interact closely with their environment. The warmer, more drought-stressed trees harbor more successful pests than cooler, less drought-stressed trees. As cities and natural habitats become hotter and drier, damaging insects will become more abundant on urban trees.
Trees within urban forests are valuable economically and for the environmental sustainability (可持续性) of the region. More than half of the world’s population lives in cities. Across the globe, people are moving into cities at a faster rate than ever. Rapid growth may turn cities into places with harder conditions. Although cities are primarily made of buildings, roads, parking lots, and vehicles, there are still plants in them. The trees within a city are referred to as the urban forest. Urban forests offer very big benefits to human and environmental health. They improve air and water quality, provide habitat for wildlife, cool down temperatures and beautify our environment. They make cities livable.
However, being a city tree is not easy. Heat released by human activities is trapped in cities. As a result, temperatures in urban areas are often warmer than their surrounding rural areas. We call this urban warming or the urban heat island effect. Urban habitats are mostly made of surfaces of asphalt (沥青) and concrete. These surfaces reduce the amount of rainwater that reaches tree roots. As a result, urban forests may suffer, which can negatively affect people and the environment.
What can we do to restore urban forests? Regular irrigation when possible may help keep pest populations under control. Planting tree species that are suitable to handle heat and drought stress would also reduce the occurrence of insect pest outbreaks.
1.What makes tree pests more successful in the city than in rural areas?
A. The warmer and rainy habitat.
B. The hotter and drier habitat.
C. The cooler and drier habitat.
D. The hotter and rainy habitat.
2.Urban forests make cities livable by .
A. providing people enough clean water
B. improving the living environment
C. offering people economic benefits
D. lowering the temperatures
3.According to the text, what results in the city trees’ suffering?
A. Natural disasters.
B. Invisible forces.
C. Human activities.
D. Natural evolution.
4.What would be the best title for the text?
A. The Importance of the Urban Trees
B. How to Protect the Urban Trees
C. Urban Trees Are in Great Danger
D. Let’s Act for the Protection of Urban Trees
高三英语阅读理解困难题查看答案及解析