【正确答案】
D
【答案解析】[听力原文] Air pollution is the biggest environmental health risk in the world, says the World Health Organization. Part of the problem is particulate matter, very small particles floating in the air. Particulate matter, also known as PM, may get trapped in the lungs. Scientists have long known about the harmful effects of breathing PM. The particulates are linked to an increased risk of breathing problems, heart attacks, strokes and lung cancer. A U.S. based team has been studying the issue. Its members are environmental engineers and public health researchers. The team recently prepared a model to show how much people would be helped if air pollution from PM is cut to the WHO's suggested limits. Joshua Apte is an assistant professor of envi- ronmental engineering at the University of Texas, Austin. He led the study. 'About 75 percent of the total number of deaths that could be avoided from cleaner air could come from improving air in some of the most polluted parts of the world, like India and China.' He adds that improving air quality could bring as many health benefits as when we take steps to deal with major diseases like AIDS. The study estimates that reducing air pollution around the world could save 1.4 million people in places like India and China. But that is not an easy goal. The report says that even to reduce mortality rates in half, India and China would need to cut pollution levels by almost 70 percent from their 2010 lev- els. In places like New Delhi, PM levels are sometimes 10 times higher than the amount set in the WHO's air quality guidelines. India and China are home to some of the world's most polluted cities. Thirteen of the world's 20 most polluted cities are in India. The capital, New Delhi, is at the top of the list. The study also shows that even if the pollution levels stay the same, death rates Would jump by over 20 percent in India and China. Joshua Apte explains that the main reason for this increase is population changes in these coun- tries over time. He notes that as the population gets older over time, the number of people at risk of heart attack or stroke goes up. But it may be difficult for India and China to improve air quality since both countries still use coal for electricity. Many roads are becoming filled with vehicles owned by the growing middle class. China has done some work in cleaning the air. But experts believe that air pollution could worsen in India. They worry that India wants to increase the number of coal-powered plants to fuel the country's economy. They expressed regret that Indian officials have taken little action to limit air pol- lution. What do we learn about particulate matter? 选项都是关于某种物体的陈述和诊断，故听音时注意留意相关信息。录音提到，悬浮颗粒与增加患呼吸道疾病、心脏病、中风以及肺癌的风险有关系。故D项正确。 干扰项排除：录音提到空气污染是世界上最大的环境健康风险，PM只是空气污染问题的一个部分，故A项错误。录音中提到悬浮颗粒是悬浮在空中的微小颗粒，并不局限于upper air“高空”，B项也错误。科学家早就知道吸入悬浮颗粒的危害，C项刚好相反。
【正确答案】
A
【答案解析】[听力原文] For what did the research team prepare a model? 选项都是不定式结构，问题可能问原因或目的。录音中提到研究团队通过准备一个模型，是想告诉我们如果空气污染被降低到世界卫生组织制定的标准，将有多少人会受益，即免于死亡。南此可知，人类的健康与空气质量息息相关，A项最为接近原文意思。 干扰项排除：录音没有提到如何降低空气污染的问题，故B项“如何有效降低空气污染”错误。讲话人只提到如果一些污染重的国家如印度、中国的空气质量提高，将会使一些因空气污染而死亡的人数减少，但并没有说C项“死亡率上升主要是空气污染引起的”。讲话人未提到如何解决心脏病及呼吸疾病，故D项错误。
【正确答案】
C
【答案解析】[听力原文] What do we learn about New Delhi,according to the study? 根据选项出现的Here、China、places等关键词，推测问题可能问某个地方的相关信息。录音提到世界上污染最重的20个城市，印度占了13个。同时也提到印度首都新德里在该列表中排名第一，故C项正确。 干扰项排除：该研究估计，减少空气污染将会拯救印度和中国等地区的140万的人口，并非单指新德里，故A项错误。录音提到新德里的PM含量有时候比世界卫生组织空气质量参考设定的量高10倍，并没有与中国对比，故B项也错误。如果中印两国的污染程度保持不变，死亡率将会上升20％，这是假设情况，D也不能选。