Questions 47 to 51 are based on the following passage. Last year, our nation’s capital passed the murder-a-day mark, and the number of homicides is now up some 50 percent from that level. More than half of these killings are drug-related. In 1988 New York City had its most violent year ever, with 1896 homicides. Many of these in volved drugs. Such homicides are also a problem in Detroit, Baltimore, St. Louis, Los Angeles, Phoenix and scores of other cities where drug gangs war against one another and use violence to spread their deadly trade. In Bankhead Courts, and Atlanta housing project, drug-related crime has reached the point where mail carriers have had to depend on increased police patrols at delivery, time. What is happening around us unfolds a vivid picture that the links between drug use and crime are clearly established. According to authoritative governmental study, around three-quarters of crack and heroin users claim they commit crime to feed their habit. In consequence, a huge rise in drug-related crime is undermining the Government’s attempts to crack clown on lawlessness in the nation. It is our priority to break this damaging chain. For years, we have attacked the supply side of the drug crisis, trying to choke off the flow of drugs into our country and stop the networks that distribute them. This strategy has failed miserably. Now it’s time to launch a whole new offensive. We must crack down on drug consumers. Last year, former First Lady Nancy Reagan had an emotional meeting with the parents of a young woman who had died in a train crash that involved an engineer’s use of drugs. After that meeting, Mrs. Reagan said, "If you’re a casual drug user, you’re an accomplice to murder." Mary’ Jane Hatcher, widow of a New York City drug-enforcement agent killed in the drug wars, echoes that sentiment. "Even through the grief," she said after her husband’s death earlier this year, "I must ask who really killed Everett Emerson from our society Look around. We middle-class suburban Americans, we casual users, we dabblers (涉猎着) in drugs keep the market in drugs an ever-increasing one. Therefore, Everett Emerson Hatcher was killed by all of us nice people, all of you who hear me now and fit this description, all of you must accept the blame for the loss of this good, gentle man.\ The story about mail carriers shows that ______.