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Questions 21 to 25 are based on the following passage. Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Cle

题目

Questions 21 to 25 are based on the following passage. Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide 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 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 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 (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、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
参考答案和解析
正确答案:D
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相似问题和答案

第1题：

The McDonald's is the largest employer in the United States.()


正确答案：错

第2题：

In the 1960s, many young Americans were dissatisfied with American society. They wanted to end the Vietnam War and to make all of the people in the U.S. equal. Some of them decided to "drop out" of American society and form their own societies . They formed utopian communities , which they called "communes," where they could follow their philosophy of "do your own thing." A group of artists founded a commune in southern Colorado called "Drop City." Following the ideas of philosopher and architect Buckminster Fuller they built domeshaped houses from pieces of old cars. Other groups, such as author Ken Kesey's Merry Pranksters, the followers fo San Francisco poet Steve Gakin, and a group that called itself the Hog Farm, lived in old school huses and traveled around the United States. The Hog Farm become famous when they helped organize the Woodstock Rock Festival in 1969. Steve Gaskin's followers tried to settle down on a farm in Tennessee, but they had to leave when some members of the gruop were arrested for growing marijuana.
Not all communes believed in the philosophy of "do you own thing," however . Twin Oaks , a commune founded in Virgiania in the late 1960s, was based on the ideas of psychologist B.F.Skinner. The people who lived at Twin Oaks were carefully controlled by Skinner's "conditioning" techniques to do things that were good for the community. In 1972, Italian architect Paolo Soleri began to build Arcosanti, a utopian city Arizsona where 2500 people will live closely together in one large building called an "archology" Soleri believes that people must live closely together so that they will all become one.
What was the Twin Oaks commune base on ?

a.The philosophy of "do your own thing"
b.Virginaia in the late 1960s
c.The ideas of psychologist
d.The belief that people must live closely togerher.

答案：C
解析：

第3题：

Which of the following statements about labor unions can be concluded based on the information in the passage?

A. Labor unions reached their peak of power in the 1986's.

B. It. took labor unions many years to improve conditions for workers.

C. The early labor unions failed .because they were not concerned with the well-being of workers.

D. The early labor unions failed because they could not agree on what they wanted to fight for.


正确答案：B
此题是对主题思想的推理判断。其中concluded．．．based on the passage为关键词语。它要求读者避开过于细节性的选择，也不能选择过于笼统的答案，致使选项中包含的内容超越文章的范围。读者应抓住情节用排除法将与文章不相干的A(1986's工会鼎盛)，C(不关心工人福利)，D(未达成一致奋斗目标)选项排除掉。只有B项“工会经过多年(1869-1930)努力奋斗才改善了工人的工作条件”与文章内容一致。

第4题：

共用题干
New research from NASA scientists suggests emissions of black soot after the way sunlight re- flects off snow.According to a computer simulation,black soot may be responsible for 25 percent of observed global warming over the past century. Soot in the higher latitudes（维度）of the Earth,where ice is more common , absorbs more of the sun's energy and warmth than an icy,white background. Dark-colored black carbon,or soot, absorbs sunlight,while lighter colored ice reflects sunlight.
Soot in areas with snow and ice may play an important role in climate change.Also,if snow and ice covered areas begin melting,the warming effect increase,as the soot becomes more con-centrated on the snow surface.“This provides a positive feedback,as glaciers and ice sheets melt, they tend to get even dirtier.”said Dr. James Hansen,a researcher at NASA's Goddard Institute for Space Studies,New York.
Hansen found soot's effect on snow albedo（反照率）,which may be contributing to trends to-ward early springs in the Northern Hemisphere,such as thinning Arctic sea ice and melting glac-iers permafrost. Soot also is believed to play a role in changes in the atmosphere above the oceans and land.
“Black carbon reduces the amount of energy reflected by snow back into space,thus heating the snow surface more than if there were no black carbon,”Hansen said. Soot's increased absorp-tion of solar energy is especially effective in warming the world's climate.“ This forcing is unusual-ly effective,causing twice as much global warming as a carbon-dioxide forcing of the same magni-tude.”Hansen noted.
Hansen cautioned,although the role of soot in altering global climate is substantial,it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century .Such gases are expected to be the largest climate forcing for the rest of the century.
The researchers found that observed warming in the Northern Hemisphere was large in the winter and spring at middle and high latitudes. These observations were coherent with the researchers' climate model situations,which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.

Which of the following statements of soot is NOT true?
A: It absorbs sun's heat.
B: It is responsible for climate change.
C: It reflects sunlight.
D:.It may account for a quarter of global warming over the past century.

答案：C
解析：
文章第二段最后一句“…while lighter colored ice reflects sunlight.”说浅色的冰反射太阳光，而黑色的煤烟灰并不反射。其他三项在文章一、二段都有提到，故本题选C。


根据第五段首句“Black carbon reduces the amount of energy reflected by snow back in-to space, thus heating the snow surface more than if there were no black carbon,”可知，黑炭覆盖的地区有更强烈的加热效果。故本题选B。


第五段中的“This forcing”指的是其前面所说的“Soot's increased absorption of solar energy”。因此本题选B。


根据第六段“…it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century.”可知，温室气体是上世纪气候变暖的首要原因，故选C。


由最后一段最后一句“…which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.”知，部分大规模的温室效应发生在有厚雪覆盖层和阳光强烈的地方。故本题选C。

第5题：

共用题干
New research from NASA scientists suggests emissions of black soot after the way sunlight re- flects off snow.According to a computer simulation,black soot may be responsible for 25 percent of observed global warming over the past century. Soot in the higher latitudes（维度）of the Earth,where ice is more common , absorbs more of the sun's energy and warmth than an icy,white background. Dark-colored black carbon,or soot, absorbs sunlight,while lighter colored ice reflects sunlight.
Soot in areas with snow and ice may play an important role in climate change.Also,if snow and ice covered areas begin melting,the warming effect increase,as the soot becomes more con-centrated on the snow surface.“This provides a positive feedback,as glaciers and ice sheets melt, they tend to get even dirtier.”said Dr. James Hansen,a researcher at NASA's Goddard Institute for Space Studies,New York.
Hansen found soot's effect on snow albedo（反照率）,which may be contributing to trends to-ward early springs in the Northern Hemisphere,such as thinning Arctic sea ice and melting glac-iers permafrost. Soot also is believed to play a role in changes in the atmosphere above the oceans and land.
“Black carbon reduces the amount of energy reflected by snow back into space,thus heating the snow surface more than if there were no black carbon,”Hansen said. Soot's increased absorp-tion of solar energy is especially effective in warming the world's climate.“ This forcing is unusual-ly effective,causing twice as much global warming as a carbon-dioxide forcing of the same magni-tude.”Hansen noted.
Hansen cautioned,although the role of soot in altering global climate is substantial,it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century .Such gases are expected to be the largest climate forcing for the rest of the century.
The researchers found that observed warming in the Northern Hemisphere was large in the winter and spring at middle and high latitudes. These observations were coherent with the researchers' climate model situations,which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.

What is the main cause of climate warming during the past century?
A: Soot.
B: Snow.
C: Greenhouse gases.
D:.Wind.

答案：C
解析：
文章第二段最后一句“…while lighter colored ice reflects sunlight.”说浅色的冰反射太阳光，而黑色的煤烟灰并不反射。其他三项在文章一、二段都有提到，故本题选C。


根据第五段首句“Black carbon reduces the amount of energy reflected by snow back in-to space, thus heating the snow surface more than if there were no black carbon,”可知，黑炭覆盖的地区有更强烈的加热效果。故本题选B。


第五段中的“This forcing”指的是其前面所说的“Soot's increased absorption of solar energy”。因此本题选B。


根据第六段“…it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century.”可知，温室气体是上世纪气候变暖的首要原因，故选C。


由最后一段最后一句“…which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.”知，部分大规模的温室效应发生在有厚雪覆盖层和阳光强烈的地方。故本题选C。

第6题：

According to the text, which of the following is true?

［A］ the popularity of gap years results from an increasing number of charities.

［B］ Prince William was working hard during his gap year.

［C］ gap years are not as fashionable as they were ten years ago.

［D］ a well-structured gap year is a guarantee of university success.


正确答案：B

第7题：

In the 1960s, many young Americans were dissatisfied with American society. They wanted to end the Vietnam War and to make all of the people in the U.S. equal. Some of them decided to "drop out" of American society and form their own societies . They formed utopian communities , which they called "communes," where they could follow their philosophy of "do your own thing." A group of artists founded a commune in southern Colorado called "Drop City." Following the ideas of philosopher and architect Buckminster Fuller they built domeshaped houses from pieces of old cars. Other groups, such as author Ken Kesey's Merry Pranksters, the followers fo San Francisco poet Steve Gakin, and a group that called itself the Hog Farm, lived in old school huses and traveled around the United States. The Hog Farm become famous when they helped organize the Woodstock Rock Festival in 1969. Steve Gaskin's followers tried to settle down on a farm in Tennessee, but they had to leave when some members of the gruop were arrested for growing marijuana.
Not all communes believed in the philosophy of "do you own thing," however . Twin Oaks , a commune founded in Virgiania in the late 1960s, was based on the ideas of psychologist B.F.Skinner. The people who lived at Twin Oaks were carefully controlled by Skinner's "conditioning" techniques to do things that were good for the community. In 1972, Italian architect Paolo Soleri began to build Arcosanti, a utopian city Arizsona where 2500 people will live closely together in one large building called an "archology" Soleri believes that people must live closely together so that they will all become one.
Why did some young Americans decide to "drop out" of scoiety during the 1960s?

a.They were not satisfied with American society.
b.They wanted to grow marijuana.
c.They wanted to go to the Vietnam War.
d.They did not want all people to be equal.

答案：A
解析：

第8题：

听力原文：W: Then certified checks, cashier's and cash letters of credit are "all variants of demand deposits.

M: Yes, that's right.

Q: Which of the following is not one form. of demand deposits?

(13)

A．Cashier's.

B．Savings certificate.

C．Cash letters of credit.

D．Certified cheeks.


正确答案：B
解析：女士谈到活期存款时提到了"certified checks"、"cashier's"、"cash letters of credit"，但没有提及"savings certificate"。

第9题：

共用题干
New research from NASA scientists suggests emissions of black soot after the way sunlight re- flects off snow.According to a computer simulation,black soot may be responsible for 25 percent of observed global warming over the past century. Soot in the higher latitudes（维度）of the Earth,where ice is more common , absorbs more of the sun's energy and warmth than an icy,white background. Dark-colored black carbon,or soot, absorbs sunlight,while lighter colored ice reflects sunlight.
Soot in areas with snow and ice may play an important role in climate change.Also,if snow and ice covered areas begin melting,the warming effect increase,as the soot becomes more con-centrated on the snow surface.“This provides a positive feedback,as glaciers and ice sheets melt, they tend to get even dirtier.”said Dr. James Hansen,a researcher at NASA's Goddard Institute for Space Studies,New York.
Hansen found soot's effect on snow albedo（反照率）,which may be contributing to trends to-ward early springs in the Northern Hemisphere,such as thinning Arctic sea ice and melting glac-iers permafrost. Soot also is believed to play a role in changes in the atmosphere above the oceans and land.
“Black carbon reduces the amount of energy reflected by snow back into space,thus heating the snow surface more than if there were no black carbon,”Hansen said. Soot's increased absorp-tion of solar energy is especially effective in warming the world's climate.“ This forcing is unusual-ly effective,causing twice as much global warming as a carbon-dioxide forcing of the same magni-tude.”Hansen noted.
Hansen cautioned,although the role of soot in altering global climate is substantial,it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century .Such gases are expected to be the largest climate forcing for the rest of the century.
The researchers found that observed warming in the Northern Hemisphere was large in the winter and spring at middle and high latitudes. These observations were coherent with the researchers' climate model situations,which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.

“This forcing” in Paragraph 5 refers to_____.
A: sun's heating on snow surface
B: soot's increased absorption of solar energy
C: carbon-dioxide's warming effect
D: snow's increased reflection of sunlight

答案：B
解析：
文章第二段最后一句“…while lighter colored ice reflects sunlight.”说浅色的冰反射太阳光，而黑色的煤烟灰并不反射。其他三项在文章一、二段都有提到，故本题选C。


根据第五段首句“Black carbon reduces the amount of energy reflected by snow back in-to space, thus heating the snow surface more than if there were no black carbon,”可知，黑炭覆盖的地区有更强烈的加热效果。故本题选B。


第五段中的“This forcing”指的是其前面所说的“Soot's increased absorption of solar energy”。因此本题选B。


根据第六段“…it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century.”可知，温室气体是上世纪气候变暖的首要原因，故选C。


由最后一段最后一句“…which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.”知，部分大规模的温室效应发生在有厚雪覆盖层和阳光强烈的地方。故本题选C。

第10题：

共用题干
New research from NASA scientists suggests emissions of black soot after the way sunlight re- flects off snow.According to a computer simulation,black soot may be responsible for 25 percent of observed global warming over the past century. Soot in the higher latitudes（维度）of the Earth,where ice is more common , absorbs more of the sun's energy and warmth than an icy,white background. Dark-colored black carbon,or soot, absorbs sunlight,while lighter colored ice reflects sunlight.
Soot in areas with snow and ice may play an important role in climate change.Also,if snow and ice covered areas begin melting,the warming effect increase,as the soot becomes more con-centrated on the snow surface.“This provides a positive feedback,as glaciers and ice sheets melt, they tend to get even dirtier.”said Dr. James Hansen,a researcher at NASA's Goddard Institute for Space Studies,New York.
Hansen found soot's effect on snow albedo（反照率）,which may be contributing to trends to-ward early springs in the Northern Hemisphere,such as thinning Arctic sea ice and melting glac-iers permafrost. Soot also is believed to play a role in changes in the atmosphere above the oceans and land.
“Black carbon reduces the amount of energy reflected by snow back into space,thus heating the snow surface more than if there were no black carbon,”Hansen said. Soot's increased absorp-tion of solar energy is especially effective in warming the world's climate.“ This forcing is unusual-ly effective,causing twice as much global warming as a carbon-dioxide forcing of the same magni-tude.”Hansen noted.
Hansen cautioned,although the role of soot in altering global climate is substantial,it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century .Such gases are expected to be the largest climate forcing for the rest of the century.
The researchers found that observed warming in the Northern Hemisphere was large in the winter and spring at middle and high latitudes. These observations were coherent with the researchers' climate model situations,which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.

Which of the following areas shows a greater warming effect?
A: Ice sea areas.
B: Areas with black carbon.
C: Areas covered with white snow.
D: Melting glaciers.

答案：B
解析：
文章第二段最后一句“…while lighter colored ice reflects sunlight.”说浅色的冰反射太阳光，而黑色的煤烟灰并不反射。其他三项在文章一、二段都有提到，故本题选C。


根据第五段首句“Black carbon reduces the amount of energy reflected by snow back in-to space, thus heating the snow surface more than if there were no black carbon,”可知，黑炭覆盖的地区有更强烈的加热效果。故本题选B。


第五段中的“This forcing”指的是其前面所说的“Soot's increased absorption of solar energy”。因此本题选B。


根据第六段“…it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century.”可知，温室气体是上世纪气候变暖的首要原因，故选C。


由最后一段最后一句“…which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.”知，部分大规模的温室效应发生在有厚雪覆盖层和阳光强烈的地方。故本题选C。

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