职称英语考试

试题来源：职称英语模拟题-综合类-概括大意
【单选题】　　Soot (煤烟) and Snow：a Hot Combination 
New research fromNASA scientists suggests emissions of black soot alter the way sunlightreflects off snow.According to a computer simulation，black soot may beresponsible for 25 percent of observed global warming over the past century. 
Soot in the higherlatitudes of the Earth，where ice is more common，absorbs more of thesun’s energy and warmththan an icy,white background.Dark-colored black carbon，or soot，absorbs sunlight,while lighter colored ice reflects sunlight. 
Soot in areas withsnow and ice may play an important role in climate change.Also，if snow and icecovered areas begin melting，the warming effect increases，as the soot becomesmore concentrated on the snow surface.”This provides a positive feedback.as glaciersand ice sheets melt，they tend to get even dirtier,”said Dr.James Hansen，a researcher atNASA's Goddard Institute for Space Studies.New York. 
Hansen found soot’s effect on snowalbedo (solar energy reflected back to space)，which may be contributing to trends toward earlysprings in the Northern Hemisphere，such as thinning Arctic sea ice，melting glaciers andpermafrost.Soot also is believed to play a role in changes in the atmosphereabove the oceans and land. 
“Black carbon reducesthe amount of energy reflected by snow back into space，thus heating the snowsurface more than if there were no black carbon‘，”Hansen said.Soot’s increased absorption of solar energy isespecially effective in warming the world’s climate. 
“This forcing isunusually effective，causing twice as much global warming as acarbon.dioxide forcing of the same magnitude.’’Hansen noted. 
Hansen cautioned，although the role ofsoot in altering global climate is substantial，it does not alter the fact that greenhouse gasesare the primary cause of climate warming during the past century.Such gases areexpected to be the largest climate forcing for the rest" of this century. 
The researchers foundthat observed warming in the Northern Hemisphere was large in the winter andspring at middle and high latitudes.These observations were consistent with theresearchers’climate modelsimulations.which showed some of the 1argest warming effects occurred whenthere were heavy snow cover and sufficient sunlight. 
1.Paragraph 3 __. 
2.Paragraph4 __. 
3.Paragraph 6 __. 
4.Paragraph 7 __. 
A Soot’s Role in Changes inthe Climate and the Atmosphere 
B Observations ofWarming in the Northern Hemisphere 
C Explanation ofIncreased Warming Effect Caused by Soot 
C Effect to ReduceSnow Albedo 
E Ways to Reduce SootEmission 

F Greenhouse Gases asthe Main Factor of G1obal Warming 
5. In the twentieth century，soot __. 
6.Hansen cautionedthat greenhouse gases__. 
7. Black soot coveredsnow and ice__. 
8. A soot forcing isunusually effective，which__. 
A produces much moreglobal warming than a carbon-dioxide forcing of the same magnitude 
B contributed to 25percent of observed global warming 
C Can producegreenhouse gases 
D absorb more of sun’s energy and warmththan white background 
E still surpass sootin warming the world’S climate during the last century 
F Can be seen mostlyin the Northern Hemisphere 

试题出处：http://www.examtiku.com/shiti/166214844.html
网考网参考答案：C、A、F、B、B、E、D、A
网考网解析：进入考试题库查看解析
大数据分析：根据网考网与考试题库的统计分析，该试题：
89%的考友选择了A选项
8%的考友选择了B选项
0%的考友选择了C选项
2%的考友选择了D选项
0%的考友选择了E选项
1%的考友选择了F选项
考友解析与评论：
 · 悲剧 好多题没有头绪 赶紧做题啊
 · 这题答案有争议，我认为选C、A、F、B、B、E、D、A
 · 没读清题就选了，多么简单的一题啊