Câu hỏi:
03/04/2020 559Read 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 “roughly” in paragraph 2 is closest in meaning to______.
Sách mới 2k7: 30 đề đánh giá năng lực DHQG Hà Nội, Tp. Hồ Chí Minh, BKHN 2025 mới nhất (600 trang - chỉ từ 140k).
Quảng cáo
Trả lời:
Đáp án C
Câu hỏi từ vựng.
Roughly (adv) = C. approximately (adv): xấp xỉ, khoảng chừng.
Các đáp án còn lại:
A. precisely (adv): chính xác.
B. harshly (adv): khắc nghiệt.
D. coarsely (adv): thô, không đúng cách.
Tạm dịch: “If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, […]”- (Thí dụ như, nếu trong một mẫu vật cụ thể lượng cacbon-14 tương đương với lượng nitơ-14, […]).
CÂU HỎI HOT CÙNG CHỦ ĐỀ
Câu 1:
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
Drying food by means of solar energy is an ancient process applying wherever climatic conditions make it possible
Câu 2:
He may be quick ______ understanding but he isn't capable ______ remembering anything
Câu 3:
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.
Although she was very old, she looked very grateful
Câu 4:
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.
“Why don’t you ask your parents for advice?” said Tom
Câu 5:
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.
I am glad that we see eye to eye on the matter of the conference location.
Câu 6:
Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
I regret going to the cinema. I wish I ______.
Câu 7:
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions
Sports clear my mind. They also help me maintain a healthy lifestyle
về câu hỏi!