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The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in...
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The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.

Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in brine for (6) _______ to six months, (7) ________ being left in the open air to give (8) _______ back their dark color. They are then packed in fresh brine to be sold. In the Spanish and American methods, the fruit is harvested much earlier (9) ________ in the Greek method, producing a sweeter fruit which is often green (10) ________ colour.

The olives may also (11) _______ pressed to produce olive oil, (12) _______ is used in cooking. Italian, Spanish and Greek cuisines all (13) _______ use of this oil, giving Mediterranean dishes a unique flavor. (14) _______ is supposed to be healthier than other cooking oils and is sometimes given as one reason (15) _______ people in Mediterranean countries seem not to suffer from heart attacks in high numbers.

Giúp mình với, mình cần gấp! tks

0
The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in...
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The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.

Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in brine for (6) _______ to six months, (7) ________ being left in the open air to give (8) _______ back their dark color. They are then packed in fresh brine to be sold. In the Spanish and American methods, the fruit is harvested much earlier (9) ________ in the Greek method, producing a sweeter fruit which is often green (10) ________ colour.

The olives may also (11) _______ pressed to produce olive oil, (12) _______ is used in cooking. Italian, Spanish and Greek cuisines all (13) _______ use of this oil, giving Mediterranean dishes a unique flavor. (14) _______ is supposed to be healthier than other cooking oils and is sometimes given as one reason (15) _______ people in Mediterranean countries seem not to suffer from heart attacks in high numbers.

Giúp mình với, mình cần gấp! Thanks👉🏻👈🏻

1
23 tháng 1 2021

1. Grow up.

3.as

9.than

11.in.

14. There

15.for

23 tháng 1 2021

Còn mấy câu kia nx bn ơi!

giúp mk với!🥺

 

The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in...
Đọc tiếp

The olive tree is among the longest living trees known in Europe. It can grow (1) ______ an age of 1500 years and has (2) ______ valued since ancient times for its fruit. It is cultivated in the Mediterranean, as well (3) ______ in other places like South America and Australia.

Fresh olives are incredible and have (4) ______ very bitter taste. In other to get (5) _______ of this bitterness, three main methods are used: Greek, Spanish and American. In the Greek method, the mature fruit are put in brine for (6) _______ to six months, (7) ________ being left in the open air to give (8) _______ back their dark color. They are then packed in fresh brine to be sold. In the Spanish and American methods, the fruit is harvested much earlier (9) ________ in the Greek method, producing a sweeter fruit which is often green (10) ________ colour.

The olives may also (11) _______ pressed to produce olive oil, (12) _______ is used in cooking. Italian, Spanish and Greek cuisines all (13) _______ use of this oil, giving Mediterranean dishes a unique flavor. (14) _______ is supposed to be healthier than other cooking oils and is sometimes given as one reason (15) _______ people in Mediterranean countries seem not to suffer from heart attacks in high numbers.

Mng làm giúp mình với, xin đừng làm vài 3-4 câu

0
III. You are going to read an article about a national vote for people’s favourite tree. Six sentences have been removed from the article. Choose from the sentences A-G the one which fits each gap (16). There is one extra sentence which you do not need to use. TREE OF THE YEAR The aim of the national Tree of the Year competition is to promote and celebrate the most interesting trees around the country. Images and descriptions of a shortlist of 28 trees are put online and the public are asked...
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III. You are going to read an article about a national vote for people’s favourite tree. Six sentences have been removed from the article. Choose from the sentences A-G the one which fits each gap (16). There is one extra sentence which you do not need to use.

TREE OF THE YEAR

The aim of the national Tree of the Year competition is to promote and celebrate the most interesting trees around the country. Images and descriptions of a shortlist of 28 trees are put online and the public are asked to vote for their favourite.

The four trees that gain the most votes before 5 p.m. on 5th October will be given a grant of £1,000. In addition, all trees that receive 1,000 or more votes will get a grant of £500. The grants may be spent on a tree health check or advice from a tree expert, or an educational event, for example. (82) ………………. Among the 28 shortlisted trees there are a wide range of tree species, each with its own unique, fascinating story. For example, the ‘Ding Dong’ tree is a copper beech tree growing in a primary school playground. It was named the ‘Ding Dong’ tree because of a game pupils invented in which they race to touch its trunk, shouting ‘Ding Dong!’ The protective space underneath the 50-year-old tree is used as a magical outdoor classroom, while the indoor classroom displays pictures of the tree through each season of the year. (83) ……………….

Many of the other trees in the competition are remarkable for their age alone. The Craigends Yew, for example, is thought to be up to 700 years old, making it one of the oldest in Scotland. It is an amazing sight as many of its branches have layered. (84) ………………. As a result of these extra growths, the total size when measured around the tree’s crown (the main body of its leaves and branches) is a massive 100 metres.

Another very old tree, the Holm Oak in Kilbroney Park, Northern Ireland, is much loved by local people. It measures 3.6 metres around the trunk, and its beautiful bark looks like the skin of a snake. (85) ………………. The advantage of this lack of uprightness is that young children can climb safely and easily on it. Kilbroney Park is home to many remarkable trees, but this tree was chosen as the favourite by community members.

A 500-year-old veteran oak tree stands in the ancient woodland pasture at Carngafallt in Wales. One of the interesting things about this twisted, hollow tree is that it has several ‘air trees’ growing out of it. An ‘air tree’ is one growing without its roots touching the ground. (86) ………………. It extends its roots down inside the oak’s hollow trunk.

The original Bramley apple tree in Nottinghamshire is younger than many in this competition, but is the famous parent of all modern Bramley apple trees. (87) ………………. Many years later, Matthew Bramley, the new owner of the tree, was carrying some of his fruit when he met a gardener called Henry Merryweather. Henry asked if he could take some cuttings from Matthew's trees to grow his own trees. Mr Bramley agreed, provided they were named ‘Bramley's Seedling’.


A. This means that they are touching the ground and have taken root.

B. These roots have become enormous with age and have now emerged above the ground. Children love to jump over them like horses in a race.

C. But the most distinctive thing about this tree is that its main trunk is leaning towards the ground at an angle of 45 degrees. D. The best example of this on the big old tree is another species of tree called a rowan.

E. Alternatively, they could be used to hold a community event in honour of the tree. F. It was planted from a seed in 1809 by a woman called Ann Brailsford.

G. Children hang bird feeders from its branches and it is used as the focus of many of the educational activities going on around it.

0
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 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...
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 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 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.

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.

The word “it” in paragraph 1 refers to______.

A. carbon dating

B. the age

C. any organic natural material

D. archeology

1
25 tháng 11 2018

Đáp án A

Từ “it” ở đoạn 1 ám chỉ tới ______.

A. phương pháp xác định niên đại bằng carbon. 

B. tuổi. 

C. bất kỳ chất hữu cơ tự nhiên. 

D. khảo cổ học. 

“it” đứng đầu câu làm chủ ngữ nên ta đọc lên cả câu phía trên. 

Tạm dịch: “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” – (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). 

=> Dựa và ngữ cảnh của câu thì “it” chỉ có thể là ám chỉ cho “Carbon dating”.

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...
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 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

The word “it” in paragraph 1 refers to______. 

A. carbon dating

B. the age

C. any organic natural material 

D. archeology 

1
4 tháng 7 2019

Đáp án A

Từ “it” ở đoạn 1 ám chỉ tới ______.

A. phương pháp xác định niên đại bằng carbon.

B. tuổi.

C. bất kỳ chất hữu cơ tự nhiên.

D. khảo cổ học.

“it” đứng đầu câu làm chủ ngữ nên ta đọc lên cả câu phía trên.

Tạm dịch: “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” – (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).

=> Dựa và ngữ cảnh của câu thì “it” chỉ có thể là ám chỉ cho “Carbon dating”.

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...
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 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 is implied in the passage that______. 

A. carbon dating has no known uses outside of archeology.

B. fossils cannot be age-dated using carbon-14

C. carbon dating could not be used on an item containing nitrogen

D. carbon-14 does not have the longest known half-life

1
24 tháng 10 2018

Đáp án D

Đoạn văn ngụ ý rằng______.

A. phương pháp xác định niên đại bằng các-bon không được biết đến ngoài nghành khảo cổ học.

B. hóa thạch không thể xác định được niên đại bằng cách sử dụng carbon-14.

C. phương pháp xác định niên đại bằng các-bon không thể sử dụng trên vật có chứa ni-tơ.

D. carbon-14 không có chu kỳ bán rã dài nhất được biết đến.

Từ câu 48 ta suy ra vẫn còn có chất khác có chu kì bán rã dài hơn carbon-14 để xác định được niên đại của những cổ vật trên 80,000 tuổi