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行食管吞钡检查,见到下列哪个征象,有助于确定前述之诊断()A.局部食管黏膜影是串珠样改变B.未见明
行食管吞钡检查,见到下列哪个征象,有助于确定前述之诊断()
A.局部食管黏膜影是串珠样改变
B.未见明显异常影像,食管运动良好
C.食管下端呈光滑的鸟嘴状狭窄
D.黏膜光滑完整,食管腔外压迫
E.食管黏膜皱襞增粗断裂,局限性管壁僵硬
![](https://lstatic.shangxueba.com/sxbzda/h5/images/tips_org.png)
行食管吞钡检查,见到下列哪个征象,有助于确定前述之诊断()
A.局部食管黏膜影是串珠样改变
B.未见明显异常影像,食管运动良好
C.食管下端呈光滑的鸟嘴状狭窄
D.黏膜光滑完整,食管腔外压迫
E.食管黏膜皱襞增粗断裂,局限性管壁僵硬
第1题
The study published in the journal Nature indicates that ______.
A.the Clean Air Act has not produced the desired results
B.lead deposits in arctic snow are on the increase
C.lead will stay in soil and snow longer than expected
D.the US is the major source of lead pollution in arctic snow
第2题
《1991年民权法案》(Civil Right Act of 1991,CRA 1991)
第4题
Letters to the editor enable readers of a medical journal to express comments on______.
A.any medical event
B.articles published in the same issue
C.articles published in that journal
D.medical development
第5题
Letters to the editor enable readers of a medical journal to express comments on ______.
A.any medical event
B.articles published in the same issue
C.articles published in that journal
D.medical development
第6题
A study published recently in the journal Nature shows that airborne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic snow were declining.
In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.
In a study published in the journal Ambio, scientists found that lead levels in soil in the North-United States had decreased markedly since the introduction of unleaded gasoline.
Many scientists had believed that the lead would stay in soil and snow for a longer period.
The authors of the Am/do study examined samples of the upper layers of soft taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.
Scientists say both studies demonstrate that certain parts of the ecosystem respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.
The study published in the journal Nature indicates that ______
A.the Clean Air Act has not produced the desired results
B.lead deposits in arctic snow are on the increase
C.lead will stay in soil and snow longer than expected
D.the US is the major source of lead pollution in arctic snow
第7题
A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining.
In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate the lead sources. The dominant lead ratio found in Greenland snow matched that found ingasoline from the United States.
In a study published in the journal Ambio, scientists found that levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline.
Many scientists had believed that the lead would stay in soil and snow for a longer period.
The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.
Scientists say both studies demonstrate that certain parts of the ecosystem respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.
The study published in the journal Nature indicates that
A.the Clean Air Act has not produced the desired results.
B.lead deposits in arctic snow on the increase.
C.lead will stay in soil and snow longer than expected.
D.the U.S. is the major source of lead pollution in arctic snow.
第8题
A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining.
In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.
In a study published in the journal Ambio, scientists found that lead levels in soil in the North-eastern United States had decreased markedly since the introduction of unleaded gasoline.
Many scientists had believed that the lead would stay in soil and snow for a longer period.
The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.
Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统)respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.
The study published in the journal Nature indicates that______.
A.lead deposits in arctic snow are on the increase
B.the Clean Air Act has not produced the desired results
C.the US is the major source of lead pollution in arctic snow
D.lead will stay in soil and snow longer than expected
第9题
Letters to the editor enable readers of a medical journal to express comments on______.
A.any medical event
B.articles published in the same issue
C.articles published in that journal
D.medical development
第10题
The scientists' attitude towards the study published in the journal science is
A.skeptical.
B.enthusiastic.
C.astonished.
D.indifferent.
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