Since 1939, numerous studies have been conducted to determine whether smoking is a health hazard. The trend of the evidence has been consistent and indicates that there is a serious health risk. Research teams have conducted studies that show beyond all reasonable doubt that tobacco smoking is associated with a shortened life expectancy¹.

    Cigarette smoking is believed by most research workers in this field to be an important factor in the development of cancer of the lungs and cancer of the throat and is believed to be related to cancer of some other organs of the body. Male cigarette smokers have a higher death rate from heart disease than non-smoking males. Female smokers are thought to be less affected because they do not breathe in the smoke so deeply.

    Apart from statistics, it might be helpful to look at what tobacco does to the human body. Smoke is a mixture of gases, vaporized chemicals, minute particles of ash and other solids. There is also nicotine, which is powerful poison, and black tar. As smoke is breathed in, all those components from deposits on the membranes of the lungs. One point of concentration is where the air tube and bronchus divides. Most lung cancer begins at this point.

    Filters and low tar tobacco² are claimed to make smoking to some extent safer, but they can only slightly reduce, not eliminate the hazards.

词汇：

vaporize  /"veɪpəraɪz/  v．(使)蒸发   

bronchus /ˈbrɒŋkəs/  n．支气管

nicotine  /ˈnɪkəti:n/   n．尼古丁   

filter /"fɪltə(r)/   n．过滤嘴

membrane /"membreɪn/ n.孔．膜

注释：

1.1ife expectancy：预期寿命

Smoking may induce lung cancer

A:Right B:Wrong C:Not mentioned

Text 1
Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself, Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so
Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyse the smoking habits of twins. Her results suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced.
The Netherlands Twin Register is a voluntary database that is prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register.
The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes),but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behaviour pattern, it suggests that a particular version of a nearby gene is influencing that feature or behaviour.
Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programmes to be customised.
Results such as Dr. Vink’s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past.

A:quitting smoking is no easy job. B:kicking the habit of smoking demands a strong will. C:some people are frustrated by failing to give up smoking. D:some people may be destined to fail quitting smoking.

Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself. Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so
Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyse the smoking habits of twins. Her results suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced.
The Netherlands Twin Register is a voluntary database that is prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register.
The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes), but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behaviour pattern, it suggests that a particular version of a nearby gene is influencing that feature or behaviour.
Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programmes to be customised.
Results such as Dr. Vink’s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past.
The author cites the example of Mark Twain to show that

A:quitting smoking is no easy job. B:kicking the habit of smoking demands a strong will. C:some people are frustrated by failing to give up smoking. D:some people may be destined to fail quitting smoking.

Section Ⅱ Reading Comprehension Part A Directions: Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. Text 1 Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself, Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyse the smoking habits of twins. Her results suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced. The Netherlands Twin Register is a voluntary database that is prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register. The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes),but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behaviour pattern, it suggests that a particular version of a nearby gene is influencing that feature or behaviour. Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programmes to be customised. Results such as Dr. Vink’s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past.

A:quitting smoking is no easy job. B:kicking the habit of smoking demands a strong will. C:some people are frustrated by failing to give up smoking. D:some people may be destined to fail quitting smoking.

Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself. Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so
Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyse the smoking habits of twins. Her results suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced.
The Netherlands Twin Register is a voluntary database that is prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register.
The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes), but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behaviour pattern, it suggests that a particular version of a nearby gene is influencing that feature or behaviour.
Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programmes to be customised.
Results such as Dr. Vink’s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past

A:quitting smoking is no easy job. B:kicking the habit of smoking demands a strong will. C:some people are frustrated by failing to give up smoking. D:some people may be destined to fail quitting smoking.

Passage 3

A:They begin to develop some diseases after quitting smoking B:They can benefit little from quitting if they are heavy smoking C:They are less likely to die after quitting even if they have serious diseases D:They may regain their health almost completely if they quit in time

Cigars Instead? Smoking one or two cigars a day doubles the risk of cancers of the lip, tongue, mouth, and throat, according to a government study. Daily cigars also increase the risk of lung cancer and cancer of the esophagus, and increase the risk of cancer of the larynx (voicebox) sixfold, say researchers at the National Cancer Institute in Bethesda, Maryland. In addition, the report revealed that smoking three or four cigars a day increased the risk of oral cancer to 8.5 times the risk for nonsmokers and the risk of esophageal cancer by four times the risk of nonsmokers. The health effects of smoking cigars is one of eight sections of the article " Cigars: Health Effects and Trends". The researchers report that, compared with a cigarette, a large cigar emits up to 90 times as much carcinogenic tobacco-specific nitrosamines "This article provides clear and invaluable information about the disturbing increase in cigar use and the significant public health consequences for the country," said Dr. Richard Klausner, director of the National Cancer Institute, in a statement. "The data are clear-the harmful substances and carcinogens in cigar smoke, like cigarettes, are associated with the increased risks of several kinds of cancers as well as heart and lung diseases," he added. " In other words, cigars are not safe alternatives to cigarettes and may be addictive. " "To those individuals who may be thinking about smoking cigars, our advices is — don’’t. To those currently smoking cigars, quitting is the only way to eliminate completely the cancer, heart and lung disease risks," warned Klausner. According to a National Cancer Institute press release, there haven’’t been any studies on the health effects on nonsmokers at cigar social events, but "... a significant body of evidence clearly demonstrates an increased lung cancer risk from secondhand smoke. " What is the main idea of the article" Cigars: Health Effects and Trends" ?

A:When it comes to cancer, cigars are not any safer than cigarettes. B:Cigars may be addictive while cigarettes are not easily so. C:cigars contain less harmful substances than cigarettes. D:Increase in cigar-smoking does not affect public health much.

Cigars Instead? Smoking one or two cigars a day doubles the risk of cancers of the lip, tongue, mouth, and throat, according to a government study. Daily cigars also increase the risk of lung cancer and cancer of the esophagus, and increase the risk of cancer of the larynx (voicebox) sixfold, say researchers at the National Cancer Institute in Bethesda, Maryland. In addition, the report revealed that smoking three or four cigars a day increased the risk of oral cancer to 8.5 times the risk for nonsmokers and the risk of esophageal cancer by four times the risk of nonsmokers. The health effects of smoking cigars is one of eight sections of the article " Cigars: Health Effects and Trends". The researchers report that, compared with a cigarette, a large cigar emits up to 90 times as much carcinogenic tobacco-specific nitrosamines "This article provides clear and invaluable information about the disturbing increase in cigar use and the significant public health consequences for the country," said Dr. Richard Klausner, director of the National Cancer Institute, in a statement. "The data are clear-the harmful substances and carcinogens in cigar smoke, like cigarettes, are associated with the increased risks of several kinds of cancers as well as heart and lung diseases," he added. " In other words, cigars are not safe alternatives to cigarettes and may be addictive. " "To those individuals who may be thinking about smoking cigars, our advices is — don’’t. To those currently smoking cigars, quitting is the only way to eliminate completely the cancer, heart and lung disease risks," warned Klausner. According to a National Cancer Institute press release, there haven’’t been any studies on the health effects on nonsmokers at cigar social events, but "... a significant body of evidence clearly demonstrates an increased lung cancer risk from secondhand smoke. " What is the main idea of the article" Cigars: Health Effects and Trends" ?

A:When it comes to cancer, cigars are not any safer than cigarettes. B:Cigars may be addictive while cigarettes are not easily so. C:cigars contain less harmful substances than cigarettes. D:Increase in cigar-smoking does not affect public health much.