填空题 A team of American scientists has 1 again that there is no safe cigarette. The scientists said that even cigarettes with low 2 of tar and nicotine are harmful. And they said that the only sure way to 3 the danger of cancer and heart disease is to stop smoking completely. The new report was made by a committee 4 the national research council.
The health dangers of tar and nicotine have been well reported and reports appear to 5 helped change American smoking customs. Fifteen years ago only about two percent of the cigarettes sold in the United States were low 6 tar and nicotine. Today more 7 forty percent are low tar and nicotine cigarettes. The new report noted that studies have been made from the years 1955 to 1975. 8 that period the average amount of tar and nicotine in cigarette was reduced by about one half. 9 during the same time lung cancer and other cancers of the breathing system increased 10 seventy percent. 11 fact, male smokers 12 thirty-five or older were more 13 to die 14 lung cancer in 1975 15 smokers of the same age twenty years early.