Researchers say people traveling in traffic are three times more likely to suffer a heart attack. They say the risk of a heart attack is greatest within an hour of being in traffic. The findings are based on a German study of almost seven hundred people who suffered heart attacks. The patients described their activities during the four days before their heart attack. Researchers found that those who had been in traffic were three times more likely to have a heart attack within one hour, compared to those who had not been in traffic. Most of those in the study had been traveling by car. But some had been on bicycles and others were on buses. Research shows that people in cars and buses are exposed to ten times the amount of pollutants as people walking on the street. That is largely because they breathe in the particles and gases released from the vehicles in front of them. Over time, these small particles speed the buildup of a sticky substance in the blood. This can cause blockages to form in the arteries around the heart and lead to a heart attack. Other studies have also linked heart trouble to stress, similar to the kind that people face while driving in heavy traffic. But the researchers of the latest study say they do not know whether the increased heart attack risk is the result of stress or pollution. They suggest it may be a combination of stress, noise and pollution. Experts say the research shows the need for cleaner vehicles and better city planning to lower the risk of the heart attack.
单选题
What is found about the participants in the German study?
【正确答案】
C
【答案解析】解析：文章第二段第一句指出，这些发现基于德国的一项针对七百名心脏病患者的研究，而“这些发现”应该在此前，即第一段提到。第一段首句提到了研究结果，乘坐交通工具的人突发心脏病的几率比不乘坐的人高三倍。C)中的a higher risk是对原文中arethree times more likely to suffer…的概括总结。由此确定C)为本题的答案。
单选题
According to the study, which of the following is the safest for people who are suffering heart attacks?