10 Đề thi kiểm tra giữa HK1 môn Tiếng Anh lớp 11 - Friends Global - Đề 4

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following sentences

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following sentences

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following sentences

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following sentences

This time tomorrow, I ________ at home

He ________ several books a month, but he doesn’t have time any more

The country's economic development plan aims to achieve a ________ economy

Customer: "Can I pay with a credit card?" - Cashier: "__________."

The findings unveiled a groundbreaking discovery in the field of medicine

He paid for his dinner on the nail, handing exact change to the waiter

The new employee showed great enthusiasm for his job

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

When (A) the dog had bitten (B) her, the lovely (C) French girl screamed (D)

She go (A) to the (B) gym every day (C) to keep her body in shape (D)

Rewrite these sentences without changing their meanings.

She started working as a secretary 4 years ago.

→ She has ___________________________________________________

There are more vehicles on the roads now.

→ There did not ______________________________________________

If Mary doesn’t save enough money, she won’t buy that house.

→ Unless ____________________________________________________

I met you somewhere, I clearly remember that.

→ I clearly remember __________________________________________

Daisy isn’t good enough to go to work. (work)

→ Daisy had better ____________________________________________

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing, has been a hot topic of debate for years. In the UK, over four million people receive housing benefit, and the government spends billions of pounds each year on the program. Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment. In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs. However, proponents of housing benefit argue that it is a necessary safety net for those who are struggling to make ends meet. (32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems. In recent years, the government has introduced a number of changes to the housing benefit system, including a cap on the amount of benefit that can be received and the introduction of a bedroom tax. These changes have been controversial, with critics arguing that they disproportionately affect the most vulnerable members of society. (33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing, has been a hot topic of debate for years. In the UK, over four million people receive housing benefit, and the government spends billions of pounds each year on the program. Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment. In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs. However, proponents of housing benefit argue that it is a necessary safety net for those who are struggling to make ends meet. (32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems. In recent years, the government has introduced a number of changes to the housing benefit system, including a cap on the amount of benefit that can be received and the introduction of a bedroom tax. These changes have been controversial, with critics arguing that they disproportionately affect the most vulnerable members of society. (33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing, has been a hot topic of debate for years. In the UK, over four million people receive housing benefit, and the government spends billions of pounds each year on the program. Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment. In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs. However, proponents of housing benefit argue that it is a necessary safety net for those who are struggling to make ends meet. (32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems. In recent years, the government has introduced a number of changes to the housing benefit system, including a cap on the amount of benefit that can be received and the introduction of a bedroom tax. These changes have been controversial, with critics arguing that they disproportionately affect the most vulnerable members of society. (33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing, has been a hot topic of debate for years. In the UK, over four million people receive housing benefit, and the government spends billions of pounds each year on the program. Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment. In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs. However, proponents of housing benefit argue that it is a necessary safety net for those who are struggling to make ends meet. (32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems. In recent years, the government has introduced a number of changes to the housing benefit system, including a cap on the amount of benefit that can be received and the introduction of a bedroom tax. These changes have been controversial, with critics arguing that they disproportionately affect the most vulnerable members of society. (33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

(32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

Housing benefit, a government assistance program aimed at helping families (29) _____ low incomes and individuals afford housing, has been a hot topic of debate for years. In the UK, over four million people receive housing benefit, and the government spends billions of pounds each year on the program. Critics argue that housing benefit creates a dependency on the government and (30) _____ individuals from seeking employment. In addition, some landlords take advantage of the program by charging (31) _____ rents that are covered by the benefit, which can contribute to rising housing costs. However, proponents of housing benefit argue that it is a necessary safety net for those who are struggling to make ends meet. (32) _____ this support, many families and individuals would be unable to afford decent housing, leading to homelessness and other social problems. In recent years, the government has introduced a number of changes to the housing benefit system, including a cap on the amount of benefit that can be received and the introduction of a bedroom tax. These changes have been controversial, with critics arguing that they disproportionately affect the most vulnerable members of society. (33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

(33) _____ the criticisms, it is likely that the demand for housing benefit will continue to grow, as the cost of housing continues to rise and wages fail to keep pace.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 38.

Physical injuries are an inherent risk when participating in sports activities. Whether engaging in high-impact contact sports or individual athletic endeavours, the human body is susceptible to various types of injuries. From minor bruises to severe fractures, sports-related injuries can have both short-term and long-term effects on an individual's physical well-being.

One common type of injury in sports is sprains and strains. These occur when ligaments or muscles/tendons are stretched or torn due to sudden movements or excessive force. Sprained ankles, strained muscles, and ligament tears are frequent occurrences in sports like basketball, soccer, and tennis.

Another prevalent injury is fractures, which are breaks or cracks in bones. These can result from direct trauma, falls, or overuse. Fractures can range from hairline fractures to complete breaks, requiring immediate medical attention and often necessitating a period of immobilisation and rehabilitation.

Concussions, particularly in contact sports such as football or rugby, are also a concern. A concussion is a traumatic brain injury caused by a sudden blow to the head, resulting in symptoms like dizziness, confusion, and memory loss. Proper diagnosis and adequate recovery time are crucial to prevent further complications.

Additionally, overuse injuries are prevalent in sports that involve repetitive motions. Examples include tennis elbow, runner's knee, and stress fractures. These injuries occur gradually over time due to excessive strain on specific body parts, often requiring rest, physical therapy, and modifications in training routines.

Which of the following can be the best title for the passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 38.

Physical injuries are an inherent risk when participating in sports activities. Whether engaging in high-impact contact sports or individual athletic endeavours, the human body is susceptible to various types of injuries. From minor bruises to severe fractures, sports-related injuries can have both short-term and long-term effects on an individual's physical well-being.

One common type of injury in sports is sprains and strains. These occur when ligaments or muscles/tendons are stretched or torn due to sudden movements or excessive force. Sprained ankles, strained muscles, and ligament tears are frequent occurrences in sports like basketball, soccer, and tennis.

Another prevalent injury is fractures, which are breaks or cracks in bones. These can result from direct trauma, falls, or overuse. Fractures can range from hairline fractures to complete breaks, requiring immediate medical attention and often necessitating a period of immobilisation and rehabilitation.

Concussions, particularly in contact sports such as football or rugby, are also a concern. A concussion is a traumatic brain injury caused by a sudden blow to the head, resulting in symptoms like dizziness, confusion, and memory loss. Proper diagnosis and adequate recovery time are crucial to prevent further complications.

Additionally, overuse injuries are prevalent in sports that involve repetitive motions. Examples include tennis elbow, runner's knee, and stress fractures. These injuries occur gradually over time due to excessive strain on specific body parts, often requiring rest, physical therapy, and modifications in training routines.

According to paragraph 3, immobilisation is _______.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 38.

Physical injuries are an inherent risk when participating in sports activities. Whether engaging in high-impact contact sports or individual athletic endeavours, the human body is susceptible to various types of injuries. From minor bruises to severe fractures, sports-related injuries can have both short-term and long-term effects on an individual's physical well-being.

One common type of injury in sports is sprains and strains. These occur when ligaments or muscles/tendons are stretched or torn due to sudden movements or excessive force. Sprained ankles, strained muscles, and ligament tears are frequent occurrences in sports like basketball, soccer, and tennis.

Another prevalent injury is fractures, which are breaks or cracks in bones. These can result from direct trauma, falls, or overuse. Fractures can range from hairline fractures to complete breaks, requiring immediate medical attention and often necessitating a period of immobilisation and rehabilitation.

Concussions, particularly in contact sports such as football or rugby, are also a concern. A concussion is a traumatic brain injury caused by a sudden blow to the head, resulting in symptoms like dizziness, confusion, and memory loss. Proper diagnosis and adequate recovery time are crucial to prevent further complications.

Additionally, overuse injuries are prevalent in sports that involve repetitive motions. Examples include tennis elbow, runner's knee, and stress fractures. These injuries occur gradually over time due to excessive strain on specific body parts, often requiring rest, physical therapy, and modifications in training routines.

The word "these" in paragraph 3 refers to _____.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 38.

Physical injuries are an inherent risk when participating in sports activities. Whether engaging in high-impact contact sports or individual athletic endeavours, the human body is susceptible to various types of injuries. From minor bruises to severe fractures, sports-related injuries can have both short-term and long-term effects on an individual's physical well-being.

One common type of injury in sports is sprains and strains. These occur when ligaments or muscles/tendons are stretched or torn due to sudden movements or excessive force. Sprained ankles, strained muscles, and ligament tears are frequent occurrences in sports like basketball, soccer, and tennis.

Another prevalent injury is fractures, which are breaks or cracks in bones. These can result from direct trauma, falls, or overuse. Fractures can range from hairline fractures to complete breaks, requiring immediate medical attention and often necessitating a period of immobilisation and rehabilitation.

Concussions, particularly in contact sports such as football or rugby, are also a concern. A concussion is a traumatic brain injury caused by a sudden blow to the head, resulting in symptoms like dizziness, confusion, and memory loss. Proper diagnosis and adequate recovery time are crucial to prevent further complications.

Additionally, overuse injuries are prevalent in sports that involve repetitive motions. Examples include tennis elbow, runner's knee, and stress fractures. These injuries occur gradually over time due to excessive strain on specific body parts, often requiring rest, physical therapy, and modifications in training routines.

The word “crucial” in paragraph 4 mostly means _____.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 38.

Physical injuries are an inherent risk when participating in sports activities. Whether engaging in high-impact contact sports or individual athletic endeavours, the human body is susceptible to various types of injuries. From minor bruises to severe fractures, sports-related injuries can have both short-term and long-term effects on an individual's physical well-being.

One common type of injury in sports is sprains and strains. These occur when ligaments or muscles/tendons are stretched or torn due to sudden movements or excessive force. Sprained ankles, strained muscles, and ligament tears are frequent occurrences in sports like basketball, soccer, and tennis.

Another prevalent injury is fractures, which are breaks or cracks in bones. These can result from direct trauma, falls, or overuse. Fractures can range from hairline fractures to complete breaks, requiring immediate medical attention and often necessitating a period of immobilisation and rehabilitation.

Concussions, particularly in contact sports such as football or rugby, are also a concern. A concussion is a traumatic brain injury caused by a sudden blow to the head, resulting in symptoms like dizziness, confusion, and memory loss. Proper diagnosis and adequate recovery time are crucial to prevent further complications.

Additionally, overuse injuries are prevalent in sports that involve repetitive motions. Examples include tennis elbow, runner's knee, and stress fractures. These injuries occur gradually over time due to excessive strain on specific body parts, often requiring rest, physical therapy, and modifications in training routines.

Which of the following is NOT TRUE according to the passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

Different greenhouse gases stay in the atmosphere _______.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

The passage mainly discusses _______ of different greenhouse effects.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 45.

Greenhouse gases trap heat in the atmosphere. This natural process is what makes the surface of the Earth warmer, making it possible for living things to survive. Greenhouse gases can be classified into four major groups.

· Carbon dioxide (CO₂) comes from the burning of fossil fuels and biological materials. When it is absorbed by plants, it is removed from the atmosphere.

· Methane (CH₄) is the by-product of the production and transportation of coal, natural gas and oil, agricultural practices and the decay of organic waste.

· Nitrous oxide (N₂O) is emitted during agricultural and industrial activities. It also originates from wastewater treatment. It is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions. Methane is removed from the atmosphere through natural processes in soil and chemical reactions in the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is much more efficient at trapping radiation.

· Fluorinated gases (CFCs) have their origins in a variety of household, commercial and industrial applications and processes. Fluorinated gases are in smaller quantities than other greenhouse gases, but they are the most potent and longest lasting ones. Fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere.

Each of these gases remain in the atmosphere for a different amount of time, ranging from a few years to thousands of years. They remain long enough to become well mixed, meaning that the amount measured in the atmosphere is roughly the same all over the world, regardless of the source of emission.