Scientists watched closely last spring as a haze of pollution, which had been tracked by satellite as it crossed the Pacific Oce

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问题    Scientists watched closely last spring as a haze of pollution, which had been tracked by satellite as it crossed the Pacific Ocean, settled over a large swath of North America from Calgary, Canada, into Arizona. Now it appears that, for the first time, researchers on both sides of  the Pacific took detailed measurements of the same plume, a cloud that contained Gobi desert dust as well as hydrocarbons from industrial pollution.
   Heather Price, a University of Washington doctoral student in chemistry, found that the amount of light reflected by the particles in the air was more than 550 percent greater than normal for that time of year. The mass of Asian air contained elevated levels of ail pollutants measured. Price said, "but the only thing that came close to being alarming was the level of particulate matter."
   The haze that settled across the western part of the country was widely reported by the news media, and it was measured as far inland as the ski slopes of Aspen, Colo.
   Readings on the western side of the Pacific came from the Aerosol Characterization Experiments, a project aimed at understanding how particles in the atmosphere affect Earth’s climate. Additional measurements were taken in the same region at the same time under a project sponsored by the National Aeronautics and Space Administration.
   Knowing the pollution was approaching Washington state, Price loaded sensing equipment aboard a rented Beechcraft on April 14 and flew to Neah Bay on the state’s Northwest coast. Taking samples at various levels from 15,000 feet to 20, 000 feet in altitude, she monitored quantities of dust, ozone, carbon monoxide and hydrocarbons. "From my copilot’s seat. the dust was thick enough to see with the naked eye." Price said.
   Now she is trying to correlate her findings with those of the two research teams operating on the other side of the Pacific, where at one point the pollution plume was larger than Japan. The huge size of the cloud showed up clearly in satellite images that gave Price plenty of warning the haze was on its way. "You can see these two blobs coming out of the deserts of Mongolia and growing over Asia, then getting swept out over the ocean and finally setting over North America," she said. She intends to continue measuring air samples off the Washington coast and will be looking for air masses with evidence of pollution originating somewhere other than Asia. "We’d like to see if we can get a signature of pollution coming from Europe because computer models suggest that European sources also can be transported across the Pacific," she said. "However, we expect that sources in Europe will contribute less than Asian sources."

选项 A、of moisture over Calgary, Canada
B、developing over Pacific Ocean
C、of industrial pollutants
D、of desert dust and hydrocarbons

答案D

解析 利用题干中的特征短语“haze of pollution”作为答案线索,同时注意备选项中的核心词/特征词(A:Calgary,Canada;B:Pacific Ocean;C:industrial pollutants;D:desert dust and hydrocarbons),这样发现答案相关句:Scientists watched closely last spring as a haze of pollution,which had been tracked by satellite as it into Arizona.(划线结构都是用一般过去时态,与题干的现在时问题不符合,因此不看)Now it appears that, for the first time,researchers on both sides of the Pacific took detailed measurements of the same plume(羽状物),a cloud that contained Gobi desert dust as well as hydrocarbons from industrial pollution.结合上下文判断“the same plume”就是问题所问的“the haze of pollution”,该划线结构直接解释了“the haze of pollution”是“既包含有戈壁沙漠的灰尘也含有来自工业污染的碳氢化合物”,因此D是答案。
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