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I. Choose the correct answers to complete the passage CARBON FOOTPRINTSEverybody has a carbon footprint - it's the (1)__________of carbon dioxide we produce with any action or activity.(2)____________carbon dioxide contributes to 'greenhouse gases', our carbon footprints have a direct impact( 3)____________the environment. You can estimate your carbon footprint on any number of popular websites: if it's (4) _________, then you're probably leading a relatively green lifestyle. But...
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I. Choose the correct answers to complete the passage 

CARBON FOOTPRINTS

Everybody has a carbon footprint - it's the (1)__________of carbon dioxide we produce with any action or activity.(2)____________carbon dioxide contributes to 'greenhouse gases', our carbon footprints have a direct impact( 3)____________the environment. You can estimate your carbon footprint on any number of popular websites: if it's (4) _________, then you're probably leading a relatively green lifestyle. But (5)__________happens if it's big?

Well, the answer is that you can (6)_________it. This modern answer to the problem is for people to contribute to balancing the negative effects of their actions by using (7) ____________ fuels, recycling, reforestation and a number of other activities which are said to contribute to a lowering of (8)_________carbon dioxide.

1. a. number b. quality c. amount d. period

2. a. As b. Although c. However d. Due to

3. a. for b. to c. on d. in

4. a. small b. large c. free d. fine

5. a. when b. what c. why d. how

6. a. replace b. reuse c. increase d. balance

7. a. fossil b. leaded c. smoky d. green

8. a. moving b. lowering c. rising d. falling

1
15 tháng 4 2022

I. Choose the correct answers to complete the passage 

CARBON FOOTPRINTS

Everybody has a carbon footprint - it's the (1)__________of carbon dioxide we produce with any action or activity.(2)____________carbon dioxide contributes to 'greenhouse gases', our carbon footprints have a direct impact( 3)____________the environment. You can estimate your carbon footprint on any number of popular websites: if it's (4) _________, then you're probably leading a relatively green lifestyle. But (5)__________happens if it's big?

Well, the answer is that you can (6)_________it. This modern answer to the problem is for people to contribute to balancing the negative effects of their actions by using (7) ____________ fuels, recycling, reforestation and a number of other activities which are said to contribute to a lowering of (8)_________carbon dioxide.

1. a. number b. quality c. amount d. period

2. a. As b. Although c. However d. Due to

3. a. for b. to c. on d. in

4. a. small b. large c. free d. fine

5. a. when b. what c. why d. how

6. a. replace b. reuse c. increase d. balance

7. a. fossil b. leaded c. smoky d. green

8. a. moving b. lowering c. rising d. falling

VIII. Write the questions for the answers.What causes carbon emissions? How can I reduce my carbon footprint?How does carbon footprint affect us? What“ is a carbon footprint?How can I calculate my carbon footprint?1. A:_____________________________________________________________________B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.2.A.___________________________________________________________________B. The burning of fossil...
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VIII. Write the questions for the answers.
What causes carbon emissions? 
How can I reduce my carbon footprint?
How does carbon footprint affect us? What“ is a carbon footprint?
How can I calculate my carbon footprint?
1. A:_____________________________________________________________________
B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.
2.A.___________________________________________________________________
B. The burning of fossil fuels in the environment.
3. A. _____________________________________________________________________________
B. Carbon emissions contribute to climate change, which can have for humans and their environment.
4.A:_________________________________________________________________________
B: You need to work out your energy use, water use and waste disposal.
5. A:_______________________________________________________________________
B: Turn off lights, TVs, computers when you do not need them. Walk or ride your bike instead of using cars. Reduce the amount of trash you create by recycle and reusing items

1
29 tháng 7 2023

Write the questions for the answers:
A: What is a carbon footprint?

B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.

A: What causes carbon emissions? 

B: The burning of fossil fuels in the environment.

A: How does carbon footprint affect us?

B: Carbon emissions contribute to climate change, which can have for humans and their environment.

A: How can I calculate my carbon footprint?

B: You need to work out your energy use, water use and waste disposal.

A: How can I reduce my carbon footprint?

B: Turn off lights, TVs, computers when you do not need them. Walk or ride your bike instead of using cars. Reduce the amount of trash you create by recycle and reusing items.

VIII. Write the questions for the answers.What causes carbon emissions? How can I reduce my carbon footprint?How does carbon footprint affect us? What“ is a carbon footprint?How can I calculate my carbon footprint?1. A:_____________________________________________________________________B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.2.A.___________________________________________________________________B. The burning of fossil...
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VIII. Write the questions for the answers.
What causes carbon emissions? 
How can I reduce my carbon footprint?
How does carbon footprint affect us? What“ is a carbon footprint?
How can I calculate my carbon footprint?
1. A:_____________________________________________________________________
B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.
2.A.___________________________________________________________________
B. The burning of fossil fuels in the environment.
3. A. _____________________________________________________________________________
B. Carbon emissions contribute to climate change, which can have for humans and their environment.
4.A:_________________________________________________________________________
B: You need to work out your energy use, water use and waste disposal.
5. A:_______________________________________________________________________
B: Turn off lights, TVs, computers when you do not need them. Walk or ride your bike instead of using cars. Reduce the amount of trash you create by recycle and reusing items

1
29 tháng 7 2023

VIII. Write the questions for the answers.

 

1. A: What is a carbon footprint?

B: It is the amount of greenhouse gases - primarily carbon dioxide released into the atmosphere by human activities.

2.A. What causes carbon emissions? 

B. The burning of fossil fuels in the environment.

3. A. How does carbon footprint affect us? 

B. Carbon emissions contribute to climate change, which can have for humans and their environment.

4.A: How can I calculate my carbon footprint?

B: You need to work out your energy use, water use and waste disposal.

5. A: How can I reduce my carbon footprint?

B: Turn off lights, TVs, computers when you do not need them. Walk or ride your bike instead of using cars. Reduce the amount of trash you create by recycle and reusing items

24 tháng 6 2021

1 carbon dioxide

2 impact

3 green lifestyle 

4 cut down on

5 energy-saving bulbs

XV. Read the passage and answer the question. A carbon footprint is the amount of carbon dioxide (CO2) released into the air by your own energy needs. You need transportation, electricity, food, clothing, and other goods. CO2 is produced by the burning of fossil fuels which is used to provide energy for your homes, by the cars you travel in and by the manufacture and transport of goods you buy. Carbon dioxide is also called greenhouse gas, which causes global warming. That is the reason why...
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XV. Read the passage and answer the question.

A carbon footprint is the amount of carbon dioxide (CO2) released into the air by your own energy needs. You need transportation, electricity, food, clothing, and other goods. CO2 is produced by the burning of fossil fuels which is used to provide energy for your homes, by the cars you travel in and by the manufacture and transport of goods you buy.

Carbon dioxide is also called greenhouse gas, which causes global warming. That is the reason why the carbon footprint is a very poweful tool to understand the impact of personal behaviours on global warming. If you want to contribute to stop global warming, the reduction of your personal carbon footprint is essential. Fist, you can reduce your carbon footprint by driving less. When possible, walk or ride a bike to avoid carbon emissions completely or use public transport in order to decrease CO emissions. Second, support using clean energy sources such as wind, solar, geothermal energy and biogas. Finally, reusing or recycling items you no longer use is also a good way to reduce your carbon footprint.

1. What is a carbon footprint?

..............................................................................

2. How is CO2 produced?

..............................................................................

3. What can carbon footprint cause?

.................................................................................

4. What should you do to stop global warming?

..................................................................................

XVI. Read the passage and choose the best answer A, B, C or D to complete the passage.

In many countries in process of industrialization, overcrowded citis present a major problem. The (1) ............ of town is mainly caused by the drift of large numbers of people from the rural areas. The only long-tẻm solution is to make (2)............. in the rural areas more attractive, which would (3)............ people to stay there. This could be achieved by providing incentives for people to go and work in the villages. Moreover, facilities in the rural areas, such as transportation, health and education services should be (4)...........

1. A. population B. popularity C. populous D. overpopulation

2. A. life B. surroundings C. atmosphere D. sights

3. A. insist B. suggest C. encourage D. persuade

4. A. invested B. improved C. impressed D. increased

1
15 tháng 5 2019

XV. Read the passage and answer the question.

A carbon footprint is the amount of carbon dioxide (CO2) released into the air by your own energy needs. You need transportation, electricity, food, clothing, and other goods. CO2 is produced by the burning of fossil fuels which is used to provide energy for your homes, by the cars you travel in and by the manufacture and transport of goods you buy.

Carbon dioxide is also called greenhouse gas, which causes global warming. That is the reason why the carbon footprint is a very poweful tool to understand the impact of personal behaviours on global warming. If you want to contribute to stop global warming, the reduction of your personal carbon footprint is essential. Fist, you can reduce your carbon footprint by driving less. When possible, walk or ride a bike to avoid carbon emissions completely or use public transport in order to decrease CO emissions. Second, support using clean energy sources such as wind, solar, geothermal energy and biogas. Finally, reusing or recycling items you no longer use is also a good way to reduce your carbon footprint.

1. What is a carbon footprint?

A carbon footprint is the amount of carbon dioxide (CO2) released into the air by your own energy needs.

2. How is CO2 produced?

CO2 is produced by the burning of fossil fuels which is used to provide energy for your homes, by the cars you travel in and by the manufacture and transport of goods you buy.

3. What can carbon footprint cause?

It can cause global warming.

4. What should you do to stop global warming?

Driving less, supporting using clean energy sources such as wind, solar, geothermal energy and biogas.

XVI. Read the passage and choose the best answer A, B, C or D to complete the passage.

In many countries in process of industrialization, overcrowded citis present a major problem. The (1) ............ of town is mainly caused by the drift of large numbers of people from the rural areas. The only long-tẻm solution is to make (2)............. in the rural areas more attractive, which would (3)............ people to stay there. This could be achieved by providing incentives for people to go and work in the villages. Moreover, facilities in the rural areas, such as transportation, health and education services should be (4)...........

1. A. population B. popularity C. populous D. overpopulation

2. A. life B. surroundings C. atmosphere D. sights

3. A. insist B. suggest C. encourage D. persuade

4. A. invested B. improved C. impressed D. increased

III-Choose the best answers to complete the sentences :1. Choose the answer which needs correcting:Doing crossword puzzles surely has beneficial effects to our brain’s memory2. The system that lets us take in oxygen and release carbon dioxide is called ................... systemA. respiratory                         B.excretory                          C. circulatory                        D.nervous3. Why do you need so much sugar ? – I ......................... a cakeA. will...
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III-Choose the best answers to complete the sentences :

1. Choose the answer which needs correcting:

Doing crossword puzzles surely has beneficial effects to our brain’s memory

2. The system that lets us take in oxygen and release carbon dioxide is called ................... system

A. respiratory                         B.excretory                          C. circulatory                        D.nervous

3. Why do you need so much sugar ? – I ......................... a cake

A. will make                           B.am going to make             C. makes                               D.will be making

4.She is bored with her current job and .................. for a new one lately

A. looks                                  B.is looking                          C. looking                             D.has looked

5. The system that works as the control panel of the body in the .................. system

A. skeletal                              B.digestive                           C. nervous                            D.circulatory

6.         involves the insertion of extremely thin needles through your skin at strategic point on your body to treat pain.

A. Herb                                  B.Traditional therapy           C. Acupuncture                    D. Massage therapy

7. Did you remeber to buy the magazine I asked you ? – Sorry, I didn’t. I ............... it when I go out again.

A. will buy                             B.am going to buy               C. am buying                        D. have bought

8. What’s that on your curtains ? – It’s a stain. I ................ them to the dry cleaner’s tomorrow.

A. will take                            B.am going to take               C. will be taken                 D. am going to be taken

9. Choose the answer which needs correcting:

Natural resources provide the raw materials that need to produce finished goods

              A                B                         C                          D

10. Choose the answer which needs correcting:  A man was in need of urgent medic care

                                                                                  A      B        C                            D

11. With children, it is important to ............... the right balance between love and discipline.

A. get                                     B.keep                                  C. have                              D. retain

12. Iron ................... for weapons and tools in the bronze following the Stone Age

A. generally used          B.was generally used        C. has been generally used   D. had generally used

13. Could you .................. doing the washing up ? – Sure.

A. help me                              B. mind                                C. give me a hand             D. do me a favor

14. They will come to our house .................... ten minutes.

A. in                                       B. to                                     C. for                                D. during

15. It is ............... to work in this city with so much noise and pollution

A. healthy                              B. health                               C. unhealthy                     D. healthful

16. Tuan: I think we should use shower instead of bath to save water. Lan: - ..........................

A. Yes, I’d love to                 B. That’s a good idea           C. I’m sorry                      D. Yes, I’ll take it

17. English is the language most often ................ by people from different countries.

A. used                                   B. use                                   C. using                             D. to use

18.Creating a habit requires encoding a new set of automatic behaviors, while .................. a habit requires a completely different approach.

A. hitting                                B. sticking                            C. beating                         D. kicking

19.    Lan: It's really cold here.       Nam: I___________   the windows.

       A. will close                       B.  am going to close     C. am going to open       D. will open

20. That man is said___ in the accident two days ago.   A. died     B. to die         C. to have die     D. has died

21. Although there are _______ questions, acupuncture appears to work.

A. answer                                  B. answerable                 C. unanswered                 D. answering

22. Stephen William Hawking ____ on 8 January, 1942 in Oxford, England.

A. born                        B. has born                  C. is born                                 D. was born

2
10 tháng 8 2021

1. Choose the answer which needs correcting:

Doing crossword puzzles surely has beneficial effects to => on our brain’s memory

2. The system that lets us take in oxygen and release carbon dioxide is called ................... system

A. respiratory                         B.excretory                          C. circulatory                        D.nervous

3. Why do you need so much sugar ? – I ......................... a cake

A. will make                           B.am going to make             C. makes                               D.will be making

4.She is bored with her current job and .................. for a new one lately

A. looks                                  B.is looking                          C. looking                             D.has looked

5. The system that works as the control panel of the body in the .................. system

A. skeletal                              B.digestive                           C. nervous                            D. circulatory

6.         involves the insertion of extremely thin needles through your skin at strategic point on your body to treat pain.

A. Herb                                  B.Traditional therapy           C. Acupuncture                    D. Massage therapy

7. Did you remember to buy the magazine I asked you ? – Sorry, I didn’t. I ............... it when I go out again.

A. will buy                             B.am going to buy               C. am buying                        D. have bought

8. What’s that on your curtains ? – It’s a stain. I ................ them to the dry cleaner’s tomorrow.

A. will take                            B.am going to take               C. will be taken                 D. am going to be taken

9. Choose the answer which needs correcting:

Natural resources provide the raw materials that need to produce finished goods

              A                B                         C                          D

10. Choose the answer which needs correcting:  A man was in need of urgent medic care

                                                                                  A      B        C                            D

11. With children, it is important to ............... the right balance between love and discipline.

A. get                                     B.keep                                  C. have                              D. retain

12. Iron ................... for weapons and tools in the bronze following the Stone Age

A. generally used          B.was generally used        C. has been generally used   D. had generally used

13. Could you .................. doing the washing up ? – Sure.

A. help me                              B. mind                                C. give me a hand             D. do me a favor

14. They will come to our house .................... ten minutes.

A. in                                       B. to                                     C. for                                D. during

15. It is ............... to work in this city with so much noise and pollution

A. healthy                              B. health                               C. unhealthy                     D. healthful

16. Tuan: I think we should use shower instead of bath to save water. Lan: - ..........................

A. Yes, I’d love to                 B. That’s a good idea           C. I’m sorry                      D. Yes, I’ll take it

17. English is the language most often ................ by people from different countries.

A. used                                   B. use                                   C. using                             D. to use

18.Creating a habit requires encoding a new set of automatic behaviors, while .................. a habit requires a completely different approach.

A. hitting                                B. sticking                            C. beating                         D. kicking

19.    Lan: It's really cold here.       Nam: I___________   the windows.

       A. will close                       B.  am going to close     C. am going to open       D. will open

20. That man is said___ in the accident two days ago.   A. died     B. to die         C. to have die     D. has died

21. Although there are _______ questions, acupuncture appears to work.

A. answer                                  B. answerable                 C. unanswered                 D. answering

22. Stephen William Hawking ____ on 8 January, 1942 in Oxford, England.

A. born                        B. has born                  C. is born                                 D. was born

10 tháng 8 2021

III-Choose the best answers to complete the sentences :

1. Choose the answer which needs correcting:

Doing crossword puzzles surely has beneficial effects to our brain’s memory

=> on

2. The system that lets us take in oxygen and release carbon dioxide is called ................... system

A. respiratory                         B.excretory                          C. circulatory                        D.nervous

3. Why do you need so much sugar ? – I ......................... a cake

A. will make                           B.am going to make             C. makes                               D.will be making

4.She is bored with her current job and .................. for a new one lately

A. looks                                  B.is looking                          C. looking                             D.has looked

5. The system that works as the control panel of the body in the .................. system

A. skeletal                              B.digestive                           C. nervous                            D.circulatory

6.         involves the insertion of extremely thin needles through your skin at strategic point on your body to treat pain.

A. Herb                                  B.Traditional therapy           C. Acupuncture                    D. Massage therapy

7. Did you remeber to buy the magazine I asked you ? – Sorry, I didn’t. I ............... it when I go out again.

A. will buy                             B.am going to buy               C. am buying                        D. have bought

8. What’s that on your curtains ? – It’s a stain. I ................ them to the dry cleaner’s tomorrow.

A. will take                            B.am going to take               C. will be taken                 D. am going to be taken

9. Choose the answer which needs correcting:

Natural resources provide the raw materials that need to produce finished goods

      => are needed

10. Choose the answer which needs correcting:  A man was in need of urgent medic care

  => medical

11. With children, it is important to ............... the right balance between love and discipline.

A. get                                     B.keep                                  C. have                              D. retain

12. Iron ................... for weapons and tools in the bronze following the Stone Age

A. generally used          B.was generally used        C. has been generally used   D. had generally used

13. Could you .................. doing the washing up ? – Sure.

A. help me                              B. mind                                C. give me a hand             D. do me a favor

14. They will come to our house .................... ten minutes.

A. in                                       B. to                                     C. for                                D. during

15. It is ............... to work in this city with so much noise and pollution

A. healthy                              B. health                               C. unhealthy                     D. healthful

16. Tuan: I think we should use shower instead of bath to save water. Lan: - ..........................

A. Yes, I’d love to                 B. That’s a good idea           C. I’m sorry                      D. Yes, I’ll take it

17. English is the language most often ................ by people from different countries.

A. used                                   B. use                                   C. using                             D. to use

18.Creating a habit requires encoding a new set of automatic behaviors, while .................. a habit requires a completely different approach.

A. hitting                                B. sticking                            C. beating                         D. kicking

19.    Lan: It's really cold here.       Nam: I___________   the windows.

       A. will close                       B.  am going to close     C. am going to open       D. will open

20. That man is said___ in the accident two days ago.   A. died     B. to die         C. to have died     D. has died

21. Although there are _______ questions, acupuncture appears to work.

A. answer                                  B. answerable                 C. unanswered                 D. answering

22. Stephen William Hawking ____ on 8 January, 1942 in Oxford, England.

A. born                        B. has born                  C. is born                                 D. was born

22 tháng 5 2020

Everybody has a carbon footprint - it's the (1) ....amount........ of carbon dioxide we produce with any action or activity

22 tháng 5 2020

Everybody has a carbon footprint - it's the amount of carbon dioxide we produce with any action or activity.

Chúc bạn học tốt!

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 13 to 50.           Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a...
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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 13 to 50.

          Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a radioactive substance such as carbon-14 has a known half-life, the amount of carbon-14 remaining in an object can be used to date that object.
          Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old.
          Carbon dating cannot be used effectively in dating objects that are older than 80,000 years. When objects are that old, much of the carbon-14 has already decayed into nitrogen-14, and the molecule amount that is left doesn’t provide a reliable measurement of age. In the case of older objects, other age-dating methods are available, methods which use radioactive atoms with longer half-lives than carbon has

It can be inferred from the passage that if an item contains more carbon-14 than nitrogen-14, then the item is______.

A. not as much as 5,570 years old

B. too old to be age-dated with carbon-14

C. too radioactive to be used by archeologists 

D. more than 5.570 years old

1
4 tháng 1 2019

Đáp án A

Có thể suy ra từ đoạn văn rằng nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì vật đó ______.

A. không đến 5.570 năm tuổi

B. quá lâu đời để có thể xác định được niên đại với carbon-14.

C. chứa quá nhiều phóng xạ để được sử dụng bởi các nhà khảo cổ.

D. trên 5.570 năm tuổi.

Dựa vào đoạn 2: “Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old.”- (Carbon-14 có thời gian bán hủy là 5,570 năm, có nghĩa là sau từng ấy năm, một nửa các nguyên tử carbon-14 đã bị phân hủy thành nitơ-14. Chính tỷ lệ carbon-14 có trong chất đó cho thấy độ tuổi của nó. Thí dụ như, nếu trong một mẫu vật cụ thể lượng cacbon-14 tương đương với lượng nitơ-14, điều đó chỉ ra rằng khoảng một nửa lượng carbon-14 đã phân hủy thành nitơ-14, và mẫu vật đó có niên đại khoảng 5,570 tuổi.). =>Nếu nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì chứng tỏ nó chưa hoàn tất chu kì bán hủy của mình kéo dài trong 5.570 năm => vật đó chưa tới 5.570 tuổi.

Dịch bài

 Phương pháp xác định niên đại bằng carbon có thể được sử dụng để ước lượng tuổi của bất kì chất hữu cơ tự nhiên nào, nó được sử dụng thành công trong lĩnh vực khảo cổ học để xác định tuổi của các cổ vật, hóa thạch cổ cũng như là trong nhiều lĩnh vực khác. Nguyên tắc làm cơ sở tiền đề cho việc sử dụng phương pháp xác định niên đại bằng carbon đó là carbon là một phần của tất cả các sinh vật sống trên trái đất. Bởi vì một chất phóng xạ thí dụ như carbon-14 có thời gian bán hủy như đã biết, lượng carbon-14 còn lại trên một vật có thể được sử dụng để xác định tuổi của vật đó.

Carbon-14 có thời gian bán hủy là 5,570 năm, có nghĩa là sau từng ấy năm, một nửa các nguyên tử carbon-14 đã bị phân hủy thành nitơ-14. Chính tỷ lệ carbon-14 có trong chất đó cho thấy độ tuổi của nó. Thí dụ như, nếu trong một mẫu vật cụ thể lượng cacbon-14 tương đương với lượng nitơ-14, điều đó chỉ ra rằng khoảng một nửa lượng carbon-14 đã phân hủy thành nitơ-14, và mẫu vật đó có niên đại khoảng 5,570 tuổi.

Phương pháp xác định niên đại bằng carbon không thể được sử dụng có hiệu quả đối với cổ vật trên 80,000 tuổi. Đối với những cổ vật có tuổi đời như vậy, phần lớn carbon-14 đã hoàn toàn phân hủy thành nitơ-14, và lượng phân tử còn lại không đáng tin cậy để đo lường được độ tuổi. Trong trường hợp đối với những cổ vật có niên đại lâu hơn, những phương pháp xác định niên đại khác mới có khả dụng, những phương pháp sử dụng các nguyên tử phóng xạ có thời gian bán hủy lâu hơn carbon.

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 43 to 50.          Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a...
Đọc tiếp

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 43 to 50.

         Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a radioactive substance such as carbon-14 has a known half-life, the amount of carbon-14 remaining in an object can be used to date that object.

        Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old.

        Carbon dating cannot be used effectively in dating objects that are older than 80,000 years. When objects are that old, much of the carbon-14 has already decayed into nitrogen-14, and the miniscule amount that is left doesn’t provide a reliable measurement of age. In the case of older objects, other age-dating methods are available, methods which use radioactive atoms with longer half-lives than carbon has.

It can be inferred from the passage that if an item contains more carbon-14 than nitrogen-14, then the item is _______.

A. not as much as 5,570 years old

B. too old to be age-dated with carbon-14

C. too radioactive to be used by archeologists

D. more than 5.570 years old

1
31 tháng 1 2018

Đáp án A.

Có thể suy ra từ đoạn văn rằng nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì vật đó_____                     

A. không đến 5.570 năm tuổi

B. quá lâu đời đ có thế xác định được niên đại với carbon-14

C. chứa quá nhiều phóng xạ để được sử dụng bởi các nhà khảo cổ.

D. trên 5.570 năm tui.

Dựa vào đoạn 2: “Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-lá, this indicates that around half of the carbon- 14 has decayed into nitrogen-14, and the sample is approximately 5.570 years old”: Carbon-14 có thời gian bán hủy 5,570 năm, nghĩa là sau từng ấy năm, một nửa các nguyên tử carbon-14 đã bị phân hủy thành nitơ-14. Chính tỷ lệ carbon-14 có trong chất đó cho thấy độ tuổi của nó. Thí dụ như, nếu trong một mẫu vật cụ thể lượng cacbon-14 tương đương với lượng nitơ- 14, điều đó chỉ ra rằng khoảng một nửa lượng carbon- 14 đã phân hủy thành nitơ-14, và mẫu vật đó có niên đại khoảng 5,570 tui.

Nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì chứng tỏ nó chưa hoàn tất chu kì bán hủy của mình kéo dài trong 5.570 năm nên vật đó chưa tới 5.570 tuổi.

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 43 to 50.          Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a...
Đọc tiếp

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 43 to 50.

          Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a radioactive substance such as carbon-14 has a known half-life, the amount of carbon-14 remaining in an object can be used to date that object.

          Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old. 

          Carbon dating cannot be used effectively in dating objects that are older than 80,000 years. When objects are that old, much of the carbon-14 has already decayed into nitrogen-14, and the molecule amount that is left doesn’t provide a reliable measurement of age. In the case of older objects, other age-dating methods are available, methods which use radioactive atoms with longer half-lives than carbon has.

It can be inferred from the passage that if an item contains more carbon-14 than nitrogen-14, then the item is______.

A. not as much as 5,570 years old

B. too old to be age-dated with carbon-14

C. too radioactive to be used by archeologists

D. more than 5.570 years old

1
25 tháng 2 2017

Đáp án A

Có thể suy ra từ đoạn văn rằng nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì vật đó ______.

A. không đến 5.570 năm tuổi

B. quá lâu đời để có thể xác định được niên đại với carbon-14. 

C. chứa quá nhiều phóng xạ để được sử dụng bởi các nhà khảo cổ. 

D. trên 5.570 năm tuổi. 

Dựa vào đoạn 2: “Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old.”- (Carbon-14 có thời gian bán hủy là 5,570 năm, có nghĩa là sau từng ấy năm, một nửa các nguyên tử carbon-14 đã bị phân hủy thành nitơ-14. Chính tỷ lệ carbon-14 có trong chất đó cho thấy độ tuổi của nó. Thí dụ như, nếu trong một mẫu vật cụ thể lượng cacbon-14 tương đương với lượng nitơ-14, điều đó chỉ ra rằng khoảng một nửa lượng carbon-14 đã phân hủy thành nitơ-14, và mẫu vật đó có niên đại khoảng 5,570 tuổi.). 

=>Nếu nếu một vật có chứa nhiều các-bon 14 hơn ni-tơ 14, thì chứng tỏ nó chưa hoàn tất chu kì bán hủy của mình kéo dài trong 5.570 năm => vật đó chưa tới 5.570 tuổi.