填空题

The study found that cigarette smoking among American (36) dropped during the past year. The drop continues a general decrease in teenage smoking rates that started in Nineteen-Ninety-Six. American health officials praised the decrease as good news in the nation’s battle against smoking. They note that smoking remains the leading cause of (37) death and disease. Smoking rates among American teenagers increased in the first half of the Nineteen-Nineties. However, teenage smoking rates have been decreasing in recent years. The University of Michigan’s Institute for Social Research (38) the latest study. The Department of Health and Human Services reported the findings. The study involved more than forty-four-thousand students in more than four-hundred schools across the United States. They were asked about past and daily use of (39) , (40) and illegal drugs. The youngest students questioned were thirteen years old. The study also involved fifteen-year-old students and seventeen-year-olds. The most notable change in the study was a (41) of the decrease in cigarette use among thirteen and fifteen-year-olds. For example, about twelve percent of thirteen-year-old students questioned reported smoking at least one (42) during the past month. Six years ago, the rate was twenty-one percent. Among fifteen-year-olds, the rate (43) from thirty percent in Nineteen-Ninety-Six to twenty-one percent last year. Tommy Thompson is the secretary of Health and Human Services. He praised the findings. (44) . The study found (45) . However, the use of one illegal drug known as Ecstasy continued to increase. Yet the rate of increase was not as great as in recent years. American health officials said they would continue to give teenagers scientific information about the serious health risks of Ecstasy and other illegal drugs. (46) .