阅读理解 Premature Smoking: A Serious Problem The third report on smoking and health from the Royal College of Physicians, which was published this month, contains important new sections on the smoking habits of children and the possible effect, on their future health. These include a twenty fold in the increase in the risk of lung cancer in heavy smokers and an increase of about three and a half times in the risk of dying from coronary(冠状的) heart disease; chronic(慢性的) oronchitis (支气管炎) and emphysema(肺气肿) are also much commoner. Teachers play an important part in determining the attitude of children to smoking, whether or not the children start to smoke, and in providing knowledge about the consequences of smoking. Whenever I see children of school age openly smoking in public, I wonder whether they really understand what they are doing. Probably most do not. I at least know that my clinical practice in lung disease will not be short of patients for the rest of my working life. About 34 percent of boys aged 15 smoke, and two thirds of this number of girls. Over the past ten years there has been a small but welcome reduction in the number of boys who smoke at this age, but an increase in the number of girls. One large study has shown that of those children who smoke more than one cigarette, as many as 85 percent become habitual (习惯的) smokers. This is partly because nicotine is one of the most dependent—producing drugs known, on a par with heroin and other hard drugs in this respect. One in three smokers start before the age of nine, some even as young as five. The causes of premature death which one-third of smokers will suffer, and of the prolonged illnesses which affect so many of them, are described in the report; its enough to say that the younger a child starts to smoke the greater are his chances of dying early. It has been shown that children who smoke have certain characteristics. Compared with nonsmokers they are more rebellious(反抗的), their work deteriorates(使变坏) as they move up school, they are more likely to leave school early, and are more often delinquent(违法的) and sexually(性的) precocious(早熟). Many of these features can be summarized as anticipation of adulthood. There are a number of factors which determine the onset(开始) of smoking, and these are largely psychological and social. They include availability of cigarettes, curiosity, rebelliousness, appearing tough, anticipation of adulthood, social confidence, example of parents and teachers, and smoking by friends and older brothers and sisters. It should be much easier to prevent children from starting to smoke than to persuades adults to give up the habit once established, but in fact, this has proved very difficult. The example set by people in authority, especially parents, health care workers, and teachers, is of prime importance. School rules should forbid smoking by children on the premises (场所). This rule has even been introduced at Summerhill School where I spent my school days. There is, however, a risk of children smoking just to rebel against the rules, and even in those schools which have tried to enforce no smoking by corporeal (肉体的) punishment there is much smoking as in other schools, Nevertheless, banning smoking is probably on balance beneficial. Teachers too should not smoke on school premises, at least not in front of children.

单选题 People who smoke heavily______.

单选题 What connection is suggested in the passage between smoking and heroin addiction?

单选题 According to the passage, a common characteristic of young smokers is that______.

单选题 What measures should be taken by schools to dissuade children from smoking?

单选题 According to the passage, one risk of banning smoking is that______.