A、A slight drop in the use of cocaine. B、A drop in the use of cigarettes. C、A sharp rise in the use of drugs. D、A rise in the us

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.