摘要
<正> Kids who smoke like to think that they areimmortal②-or at least that if they stop in time,their lungs will heal.But a report in last week'sJournal of the National Cancer Institute suggestsearly smoking may trigger③changes in DNA ④thatput young smokers at higher risk for cancer even ifthey later quit.Researchers studying lungcancerpatients round that those with the worst genetic⑤damage were not those who smoked longest butthose who started youngest.What's more,the earlierthey started,the more were the damage.
