在职申硕英语考试

根据网考网考试中心的统计分析，以下试题在2019/3/23日在职申硕英语考试习题练习中，答错率较高，为：93%
【单选题】Lead deposits, which accumulated in soil and snow during the 1960’s and 1970’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that theCleanAirAct has mandated unleaded gas use in the United States, the lead accumulation world-wide has decreased significantly.

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 byDr.CharlesBoutron, an expert on the impact of heavy metals on the environment at the NationalCenter for Scientific Research in France.
A、study byDr.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 ofEuropean,Asian andCanadian 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 journalAmbio, 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 theAmbio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in NewEngland, 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．theCleanAirAct 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

网考网参考答案：C，答错率：93%
网考网试题解析：
[解析] 细节理解题。由第二段第一句可知，“美国排放的含铅气体是格陵兰雪地中高含铅量的主要贡献者”。故选C项。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>