职称英语考试

试题来源：职称英语模拟题-综合类-阅读理解
【单选题】

Lead Pollution

Lead deposits, which accumulated in soil andsnow during the 1960’s and 70’s,were primarily the result of leaded gasoline emissions originating in theUnited States. In the twenty years that the Clean Air Act has mandated unleadedgas use in the United States, the lead accumulation worldwide has decreasedsignificantly.

A study published recently in the journalNature shows that air-borne leaded gas emissions from the United States werethe leading contributor to the high concentration of lead in the snow inGreenland. 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 atthe National Center for Scientific Research in France. A study by Dr. Boutronpublished in 1991 showed that lead levels in arctic (北极的) snow were declining.

In his new study, Dr. Boutron found the ratiosof the different forms of lead in the leaded gasoline used in the United Stateswere different from the ratios of European, Asian and Canadian gasolines andthus enabled scientists to differentiate (区分) the leadsources. The dominant lead ratio found in Greenland snow matched that found ingasoline from the United States.

In a study published in the journal Ambio(人类环境杂志), scientists found that lead levels in soil in the NortheasternUnited States had decreased markedly since the introduction of unleadedgasoline.

Many scientists had believed that the leadwould stay in soil and snow for a longer period.

The authors of the Ambio study examined samplesof the upper layers of soil taken from the same sites of 30 forest floors inNew England, New York and Pennsylvania in 1980 and in 1990. The forestenvironment processed and redistributed the lead faster than the scientists hadexpected.

Scientists say both studies demonstrate thatcertain parts of the ecosystem (生态系统) respond rapidlyto reductions in atmospheric pollution, but that these findings should not beused as a license to pollute.

1.The study published in the journal Natureindicates that

A.the US is the major source of lead pollutionin arctic snow.

B.the Clean Air Act has not produced thedesired results.

C.lead will stay in soil and snow longer thanexpected.

D.lead deposits in arctic snow are on theincrease.

2.Lead accumulation worldwide decreasedsignificantly after the use of unleaded gas in the US

A.was discouraged.

B.was prohibited by law.

C.was enforced by law.

D.was introduced.

3.How did scientists discover the source oflead pollution in Greenland

A.By analyzing the data published in journalslike Nature and Ambio.

B.By comparing the chemical compositions ofleaded gasoline used in various countries.

C.By observing the lead accumulations indifferent parts of the arctic area.

D.By studying the chemical elements of soil andsnow in Northeastern America.

4.The authors of the Ambio study have foundthat

A.forests get rid of lead pollution faster thanexpected.

B.lead deposits are widely distributed in theforests of the US.

C.lead accumulations in forests are moredifficult to deal with.

D.the upper layers of soil in forests areeasily polluted by lead emissions.

5.It can be inferred from the last paragraphthat scientists

A.feel relieved by the use of unleadedgasoline.

B.are puzzled by the mystery of forest pollution.

C.lack sufficient means to combat leadpollution.

D.still consider lead pollution a problem.

网考网参考答案：A、C、B、A、D
大数据分析：根据网考网与考试题库的统计分析，该试题：
58%的考友选择了A选项
26%的考友选择了B选项
10%的考友选择了C选项
6%的考友选择了D选项
考友解析与评论：
 · 我觉得A、C、B、A、D也不对
 · 像这种考试，没什么技术含量，全靠运气。
 · 这个答案是有歧义