2009職稱英語真題理工類B級真題：閱讀理解
導語：以下英語網為大家整理了全面的職稱英語考試歷年真題及答案解析，《職稱英語考試試題匯總：歷年真題及答案解析》供大家參考學習。更多職稱英語考試試題敬請關注英語網！
【推薦】關注英語網微信：yingyuwang2024，更快獲取真題答案及成績查詢信息。
第2部分：閱讀判斷（第16～22題，每題1分，共7分）
下面的短文后列出了7個句子，請根據短文的內容對每個句子做出判斷：如果該句提供的是正確信息，請選擇A；如果該句提供的是錯誤信息，請選擇B；如果該句的信息文中沒有提及，請選擇C.
Radiocarbon Dating
Nowadays scientists can answer many questions about the past through a technique called radiocarbon （放射性碳）， or carbon-14， dating. One key to understanding how and by something happened is to discover when it happened.
Radiocarbon dating was developed in the late 1940s by physicist Willard F. Libby at he University of Chicago. An atom of ordinary carbon， called carbon-12， has six protons（中子） and six neutrons （質子） in its nucleus. Carbon-14， or C-14， is a radioactive， unstable form of carbon that has two extra neutrons （原子核）。 It returns to a more stable form of carbon through a process called decay （衰減）。 This process involves the loss of he extra neutrons and energy from the nucleus.
In Libbys radiocarbon dating technique， the weak radioactive emissions （放射） from his decay process are counted by instruments such as a radiation detector and counter. he decay rate is used to determine the proportion of C-14 atoms in the sample being dated.
Carbon-14 is produced in the Earths atmosphere when nitrogen （氮）-14， or N-14，
interacts with cosmic rays （宇宙射線）。 Scientists believe since the Earth was formed， the mount of nitrogen in the atmosphere has remained constant. Consequently， C-14 formation is thought to occur at a constant rate. Now the ratio of C-14 to other carbon toms in the atmosphere is known. Most scientists agree that this ratio is useful for dating items back to at least 50，000 years.
All life on Earth is made of organic molecules （分子） that contain carbon atoms coming from the atmosphere. So all living things have about the same ratio of C-14
atoms to other carbon atoms in their tissues （組織）。 Once an organism （有機體） dies it tops taking in carbon in any form， and the C-14 already present begins to decay. Over time the amount of C-14 in the material decreases， and the ratio of C-14 to other carbon toms goes down. In terms of radiocarbon dating， the fewer C-14 atoms in a sample， the older that sample is.
16 Nowadays many scientists depend on radiocarbon for dating age-old objects
A Right B Wrong C Not mentioned
17 The radiocarbon dating technique is only about 40 years old
A Right B Wrong C Not mentioned
18 An atom of ordinary carbon has six protons and eight neutrons
A Right B Wrong C Not mentioned
19 Radar is used to determine the characteristics of radiocarbon
A Right B Wrong C Not mentioned
20 Radiocarbon is reliable in dating an object back to at least 50，000 years.
A Right B Wrong C Not mentioned
21 The C-14 in an organism begins to decay when it dies
A Right B Wrong C Not mentioned
22 The half-life of C-14 is about 25，000 years.
A Right B Wrong C Not mentioned
導語：以下英語網為大家整理了全面的職稱英語考試歷年真題及答案解析，《職稱英語考試試題匯總：歷年真題及答案解析》供大家參考學習。更多職稱英語考試試題敬請關注英語網！
【推薦】關注英語網微信：yingyuwang2024，更快獲取真題答案及成績查詢信息。
第2部分：閱讀判斷（第16～22題，每題1分，共7分）
下面的短文后列出了7個句子，請根據短文的內容對每個句子做出判斷：如果該句提供的是正確信息，請選擇A；如果該句提供的是錯誤信息，請選擇B；如果該句的信息文中沒有提及，請選擇C.
Radiocarbon Dating
Nowadays scientists can answer many questions about the past through a technique called radiocarbon （放射性碳）， or carbon-14， dating. One key to understanding how and by something happened is to discover when it happened.
Radiocarbon dating was developed in the late 1940s by physicist Willard F. Libby at he University of Chicago. An atom of ordinary carbon， called carbon-12， has six protons（中子） and six neutrons （質子） in its nucleus. Carbon-14， or C-14， is a radioactive， unstable form of carbon that has two extra neutrons （原子核）。 It returns to a more stable form of carbon through a process called decay （衰減）。 This process involves the loss of he extra neutrons and energy from the nucleus.
In Libbys radiocarbon dating technique， the weak radioactive emissions （放射） from his decay process are counted by instruments such as a radiation detector and counter. he decay rate is used to determine the proportion of C-14 atoms in the sample being dated.
Carbon-14 is produced in the Earths atmosphere when nitrogen （氮）-14， or N-14，
interacts with cosmic rays （宇宙射線）。 Scientists believe since the Earth was formed， the mount of nitrogen in the atmosphere has remained constant. Consequently， C-14 formation is thought to occur at a constant rate. Now the ratio of C-14 to other carbon toms in the atmosphere is known. Most scientists agree that this ratio is useful for dating items back to at least 50，000 years.
All life on Earth is made of organic molecules （分子） that contain carbon atoms coming from the atmosphere. So all living things have about the same ratio of C-14
atoms to other carbon atoms in their tissues （組織）。 Once an organism （有機體） dies it tops taking in carbon in any form， and the C-14 already present begins to decay. Over time the amount of C-14 in the material decreases， and the ratio of C-14 to other carbon toms goes down. In terms of radiocarbon dating， the fewer C-14 atoms in a sample， the older that sample is.
16 Nowadays many scientists depend on radiocarbon for dating age-old objects
A Right B Wrong C Not mentioned
17 The radiocarbon dating technique is only about 40 years old
A Right B Wrong C Not mentioned
18 An atom of ordinary carbon has six protons and eight neutrons
A Right B Wrong C Not mentioned
19 Radar is used to determine the characteristics of radiocarbon
A Right B Wrong C Not mentioned
20 Radiocarbon is reliable in dating an object back to at least 50，000 years.
A Right B Wrong C Not mentioned
21 The C-14 in an organism begins to decay when it dies
A Right B Wrong C Not mentioned
22 The half-life of C-14 is about 25，000 years.
A Right B Wrong C Not mentioned
