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27 tháng 12 2016

7^2017-7^2016=7^2016(7-1)=6.7^2016

26 tháng 6 2019

Đáp án A

Ý nào dưới đây gần nghĩa nhất với đoạn 7?
A. Những người quả quyết và có tài năng có thể dễ dàng tìm được cho mình 1 công việc tốt.
B. Bí mật của 1 cuộc phỏng vấn thành công là thí sinh phải sở hữu cho mình được những kĩ năng và có đức tính quả quyết
C. Sinh viên ra trường nên phát triển ít nhất 1 trong nhiều lĩnh vực để có thể tìm được 1 công việc phù hợp.
D. Những người có thực lực luôn luôn có thể tìm được 1 công việc tốt.
Dịch đoạn 7: “There will always be good career opportunities for people with ability, skills and determination; the secret to securing a good job is to be one of them.” – (Luôn luôn có những công việc tốt cho những người có tài và có đức tính kiên quyết; bí mật để tìm được 1 công việc tốt là ở chính bản thân họ).

9 tháng 7 2019

Đáp án là B.

Cụm “pay a visit to…”: đi thăm nơi nào đó 

Read the following passage, then choose the correct answer to each question. London is the capital city of the United Kingdom. It is the largest city in Britain. It has got the population of about 7 million people. It is a very old city which was founded by the Romans.  London is famous for many things. The original area is the City. There are thousands of offices and banks but only a few people live here. The Tower of London was built in the 11th century. It was a prison but now it is a...
Đọc tiếp

Read the following passage, then choose the correct answer to each question.

London is the capital city of the United Kingdom. It is the largest city in Britain. It has got the population of about 7 million people. It is a very old city which was founded by the Romans.  London is famous for many things. The original area is the City. There are thousands of offices and banks but only a few people live here. The Tower of London was built in the 11th century. It was a prison but now it is a museum. You can see the Crown Jewels here. Tower Bridge is near the Tower of London. It was opened in 1894. Westminster Abbey is a beautiful church where the Coronation Ceremony takes place. Westminster Abbey is in the west of London, near the Houses of Parliament, where you can see and hear the well-known clock Big Ben.  Hyde Park is the most popular park in London. At Speaker’s Corner, anybody can speak about anything except the Queen. The Queen lives in Buckingham Palace. London stands on River Thames. There are 27 bridges over the Thames in London and 8 tunnels under the river. A quick and easy way to get to different places in the city is to use an underground train. Londoners call this means of transport the “tube”. There are many famous red buses in London called double-deckers and London taxis are called black cabs.

41. The Tower of London used to be ______.

 A. a library           B. a museum                   C. a prison                               D. a church

42. The word “It” in line 4 paragraph 2 refers to _____.

A. The Tower of London    B. Big Ben       C. The Crown Jewels       D. Tower Bridge

43. The word “well-known” can be best replaced by _____.

 A. quick                B. renowned           C. beautiful                             D. charming

44. You can’t talk about ____ when you are at Speakers’ Corner.

 A. the Parliament        B. politics           C. the Queen                           D. London

45. A convenient way to get around the city is by ____.

A. tube               B. bus                     C. train                   D. car 

2
30 tháng 5 2021

41C 42D 43B 44C 45A

30 tháng 5 2021

41/C

42/D

43/B

44/A

45/A

10 tháng 3 2022

7B

8D

9B->beautiful singer

10A->to go

11B->although

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

Which of the following is NOT true about carbon-14? 

A. It and nitrogen always exist in equal amounts in any substance

B. Its half-life is more than 5,000 years

C. It can decay into nitrogen-14. 

D. It is radioactive

1
23 tháng 5 2017

Đáp án A

Câu nào dưới đây KHÔNG ĐÚNG về carbon-14?

A. Nó và nitơ luôn tồn tại với số lượng bằng nhau trong bất kỳ chất nào.

B. Thời gian bán hủy của nó là hơn 5.000 năm.

C. Nó có thể phân rã thành nitơ-14.

D. Nó là chất phóng xạ.

Các đáp án B, C, D có thông tin được tìm thấy trong bài.

B + C- Dẫn chứng ở câu đầu 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”- (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).

D- Dẫn chứng ở câu cuối đoạn 1: “Since a radioactive substance such as carbon-14 has a known half-life, […]” – (Bởi vì một chất phóng xạ thí dụ như carbon-14 có thời gian bán hủy như đã biết, […]) => Carbon-14 là một chất phóng xạ.

=> Còn lại đáp án A không đúng

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.

Which of the following is NOT true about carbon-14?

A. It and nitrogen always exist in equal amounts in any substance

B. Its half-life is more than 5,000 years

C. It can decay into nitrogen-14

D. It is radioactive

1
23 tháng 10 2018

Đáp án A

Câu nào dưới đây KHÔNG ĐÚNG về carbon-14? 

A. Nó và nitơ luôn tồn tại với số lượng bằng nhau trong bất kỳ chất nào. 

B. Thời gian bán hủy của nó là hơn 5.000 năm. 

C. Nó có thể phân rã thành nitơ-14. 

D. Nó là chất phóng xạ. 

Các đáp án B, C, D có thông tin được tìm thấy trong bài. 

B + C- Dẫn chứng ở câu đầu 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”- (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). 

D- Dẫn chứng ở câu cuối đoạn 1: “Since a radioactive substance such as carbon-14 has a known half-life, […]” – (Bởi vì một chất phóng xạ thí dụ như carbon-14 có thời gian bán hủy như đã biết, […]) => Carbon-14 là một chất phóng xạ. 

=> Còn lại đáp án A không đúng.

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.

Which of the following is NOT true about carbon-14?

A. It and nitrogen always exist in equal amounts in any substance.

B. Its half-life is more than 5,000 years.

C. It can decay into nitrogen-14.

D. It is radioactive.

1
29 tháng 4 2019

Đáp án A.

Câu nào dưới đây KHÔNG ĐÚNG về carbon-14?

A. Nó và nitơ luôn tn tại với số lượng bằng nhau trong bất kỳ chất nào.

B. Thời gian bán hủy của nó là hơn 5.000 năm.

C. Nó có th phân rã thành nitơ-14.

D. Nó là chất phóng xạ.

Các đáp án B, C, D có thông tin được tìm thấy trong bài. B + C- Dn chứng ở câu đầu 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”: Carbon-14 có thời gian bán hủy 5.570 năm, có nghĩa là sau từng ẩy năm, một nửa các nguyên từ carbon-14 đã bị phân hủy thành nitơ-14. D- Dn chứng ở câu cuối đoạn 1 : “Since a radioactive substance such as carbon-14 has a known half-life, [...]”: Bởi vì một chất phóng xạ thí dụ như carbon-14 có thời gian bán hủy như đã biết, [...])Carbon-14 là một chất phóng xạ.

Còn lại đáp án A không đúng.

Fill in each of the numbered blanks with One suitable word to complete the following pasages: People have smoked cigarettes for a long time now.The tobacco which is(1)...to make cigarettes was first grown in what is now part of the United States.Christopher Columbus,(2)...discovered American,saw the Indians smoking.Soon the dried leaves were transported to Europe where smoking began to catch on.In(3)...late 1800s,the Turks made cigarettes popular. Cigarettes smoke contains at(4)...two...
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Fill in each of the numbered blanks with One suitable word to complete the following pasages:

People have smoked cigarettes for a long time now.The tobacco which is(1)...to make cigarettes was first grown in what is now part of the United States.Christopher Columbus,(2)...discovered American,saw the Indians smoking.Soon the dried leaves were transported to Europe where smoking began to catch on.In(3)...late 1800s,the Turks made cigarettes popular.

Cigarettes smoke contains at(4)...two harmful substances,tar and nicotine.Tar,which form as the tobacco burns,damages,the lungs and(5)...affects breathing.Nicotine,which is found in the leaves,cause the heard to(6)...faster and increases the breathing rate.

Smoking(7)...is dangerous.The US Publuc Health Service ed that cigarettes smoking is the cause of lung(8)...and several other deadly(9)...The US government now requires that each package of cigarettes bears a special warning about the(10)...of smoking.

3
25 tháng 7 2017

People have smoked for a long time now. The tobacco which is used to make cigarettes was first grown in what is now part of the United States. Christopher Columbus, who discovered America, saw the Indians smoking. Soon the dried leaves were transported to Europe where smoking began to catch on. In the late 1800s, the Turk made cigarettes popular.

Cigarette smoke contains at least two harmful substances, tar and nicotine. Tar, which forms as the tobacco burns, damages the lungs and therefore affects breathing. Nicotine, which is found in the leaves, causes the heart to beat faster and increases the breathing rate.

Smoking cigarettes is dangerous. The US Public Health Service stated that cigarette smoking is the cause of lung cancer and several other deadly diseases. The US government now requires that each package of cigarettes bears a special warning about the danger of smoking.

25 tháng 7 2017

Fill in each of the numbered blanks with One suitable word to complete the following pasages:

People have smoked cigarettes for a long time now.The tobacco which is(1) use to make cigarettes was first grown in what is now part of the United States.Christopher Columbus,(2) who discovered American,saw the Indians smoking.Soon the dried leaves were transported to Europe where smoking began to catch on.In(3) the late 1800s,the Turks made cigarettes popular.

Cigarettes smoke contains at(4) least two harmful substances,tar and nicotine.Tar,which form as the tobacco burns,damages,the lungs and(5) therefore affects breathing.Nicotine,which is found in the leaves,cause the heard to(6) beat faster and increases the breathing rate.

Smoking(7) cigarettes is dangerous.The US Publuc Health Service ed that cigarettes smoking is the cause of lung(8) cancer and several other deadly(9) dieases The US government now requires that each package of cigarettes bears a special warning about the(10) danger of smoking.