Eating too much fatty food, exercising too little and smoking can raise your future risk o

Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately: the air you breathe.
Previous studies have linked high exposure (暴露）to environmental pollution to an increased risk of heart problem, but two analyses now show that poor air quality can lead to heart attack or stroke (中风）within as little as a few hours after exposure. In one review of the research, scientists found that people exposed to high levels of pollutants (污染物）were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency (EPA) considers to be of “moderate” (良好）quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.
The authors of both studies stress that these risks are relatively small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure. However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulation by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.
【小题1】The text mainly discusses the relationship between . A．heart problems and air qualityB．heart problems and exercisingC．heart problems and smokingD．heart problems and fatty food【小题2】The underlined word “modest” in Paragraph 3 most probably means .A．relatively highB．extremely lowC．relatively lowD．extremely high【小题3】What can we learn from the text? A．Eating fatty food has immediate effects on your heart.B．The EPA conducted many studies on air quality.C．Moderate air quality is more harmful than smoking,D．Stricter regulations on pollutants should be made.【小题4】The author’s purpose of writing the text is most likely to . A．informB．persuadeC．describe D．entertainA

(答案→)A 解析：众所周知，摄入过多脂肪，缺乏锻炼以及长期吸烟会增加患心脏病的风险，但最新的研究表明，另外一项我们平时不注意的东西更使我们患心脏病的风险大大增加，那就是我们所呼吸的空气。【小题1】主旨大意题。根据本文主题句——第一自然段的最后一句可知本文大意是说明空气质量和心脏病发病率之间的关系，选A。【小题2】词义猜测题。modest原意是：谦虚的，温和的，由此可以推断出本文中其意思是：相对较低的，选C。【小题3】事实细节题。根据最后一句可知本题选D。【小题4】写作意图题。本文是一篇说明文，主要意思是说明人们所呼吸的空气和心脏病的发病率之间的关系，由此可知作者的写作目的是告知人们一个事实，故本题选A。

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