题目内容
【题目】 As e-cigarettes become more popular, fewer people are taking up smoking traditional cigarettes. But can e-cigarettes, an electronic nicotine delivery system, help people quit smoking altogether? The answer is probably yes. A study led by Matthew Carpenter, a professor at the Medical University of South Carolina found that e-smokers tend to smoke less and have increased quit attempts.
In the pilot study, Carpenter evaluated e-cigarettes in terms of usage, product preference, changes in smoking behaviors and nicotine exposure. Ninety subjects were evaluated：45 were randomized to use e-cigarettes, and 45 were randomized to a control group. Everyone was followed over a period of four months. The study was published in Cancer Epidemiology in November and is one of the few randomized studies in the U. S. to examine the effects of e-cigarettes.
Results showed that when smokers were given e-cigarettes, uptake was strong. Many participants rated the e-cigarettes similar to their usual product, suggesting that e-cigarettes might give smokers a suitable alternative to combustible（燃烧的）cigarettes. E-cigarettes offer significantly less exposure to harmful toxicants and therefore are safer. People using e-cigarettes throughout the study smoked an average of 37 percent fewer cigarettes, as compared to those in the control group, showing a positive effect when making the switch and potentially serving as a tool to help smokers quit.
That's good news for Carpenter and his colleagues. Smoking is the leading cause of cancer and has a negative impact on the effectiveness of cancer treatments. People who quit smoking, regardless of their ages, have substantial gains in life expectancy（预期寿命）compared with those who continue to smoke.
Carpenter cautions that while e-cigarettes may help people smoke less or even quit, they are not for everyone. "It is important to protect non-smokers, particularly adolescents, from starting any nicotine-containing product. "
More than 1,500 varieties of e-cigarettes are now available, including different looks, high-tech power settings and many flavors. All these make them more appealing to kids. In fact, e-cigarettes are more popular than conventional cigarettes among youth. "All these should raise our alarm bells," he said.
E-cigarettes were only recently regulated by the Food and Drug Administration. Largely manufactured overseas, the quality control process varies, he says. Without enough information to answer the long-term public health issues of e-cigarettes, researchers like Carpenter are aware of the importance of further studies on the latest tobacco trends. Combustible cigarettes have been around for many decades. E-cigarettes have not, and the science has a lot of questions left to answer, he said.
【1】Which of the following is TRUE about Professor Carpenter's experiment on e-cigarettes?
A. The test groups include conventional smokers, e-smokers and non-smokers.
B. E-cigarettes expose smokers to fewer poisonous substances.
C. Many participants don't think e-cigarettes as good as traditional ones.
D. It is one of the few studies to test the effects of smoking.
【2】After reading the passage, we may infer that_______.
A. most e-cigarette smokers will finally give up smoking
B. there are more e-smokers than traditional smokes in the USA
C. many adolescents are attracted to e-cigarettes due to their low prices
D. carpenter is worried about the e-cigarettes' popularity among children
【3】What can be concluded from the last paragraph?
A. E-cigarettes are faced with many problems and need more study.
B. The U. S. government should strengthen its regulation over e-cigarettes.
C. Smokers should be cautious because of e-cigarettes' low quality.
D. Researchers are concerned about e-cigarettes' harm to people's health.
【4】What is the structure of the passage?___
（①to ⑦represent Paragraphs 1 to 7）
A. 
B. 
C. 
D. 
【答案】
【1】B
【2】D
【3】A
【4】B
【解析】
本文是一篇说明文。文章主要介绍了随着电子烟越来越流行,越来越少的人开始吸传统香烟。但是电子烟,一个电子尼古丁递送系统,能帮助人们完全戒烟吗?答案可能是肯定的。南卡罗莱纳医科大学的教授马修卡彭特（Matthew Carpenter）领导的一项研究发现,电子烟民倾向于减少吸烟,并增加戒烟的次数，但电子烟面临着许多问题,需要更多的研究。
【1】细节理解题。根据第三段中"E-cigarettes offer significantly less exposure to harmful toxicants and therefore are safer"可知电子烟使吸烟者暴露在更少的有毒物质中。故选B。
【2】细节理解题。根据倒数第三段最后一句"It is important to protect non-smokers, particularly adolescents, from starting any nicotine-containing product. （重要的是要保护非吸烟者，特别是青少年，远离任何含有尼古丁的产品。）"可知carpenter担心电子烟在儿童中的受欢迎程度。故选D。
【3】细节理解题。根据最后一段最后一句Combustible cigarettes have been around for many decades. E-cigarettes have not, and the science has a lot of questions left to answer, he said.（可燃香烟已经存在了几十年。他说，电子烟没有，科学上还有很多问题需要回答。）可知电子烟面临着许多问题,需要更多的研究。故选A。
【4】推理判断题。纵览全文可知第一段和最后一段是总写电子烟,第二三四段主要介绍了电子烟的好处、五六段介绍了电子烟不适合儿童,所以文章的结构是B选项。故选B。
