[originaltext] The use of illegal drugs by U.S. teenagers has increased in t

The use of illegal drugs by U.S. teenagers has increased in the past two years, according to the latest survey by University of Michigan researchers. The increase reverses a downward trend in drug use among teenagers that began in the late 1970s.
    Results of a survey of 50,000 eighth, tenth and twelfth graders throughout the United States indicated a sharp rise in the use of drugs. The researchers also noted an increase in the percentage of students who smoke cigarettes, a drop in the percentage of students who drink alcohol, and no change in cocaine use, which remained at a low level.
    Although the general rise in the use of drugs is disturbing, the numbers are still far below the recorded high level of drug use in the 1970s.
    A consistent drop in drug use, such as the one that occurred be- fore the recent rise, can’t be taken for granted, because each generation of American youth has almost no knowledge of drugs and has to learn the same hard lessons.