A report, published in last week's Journal of the American Medical Association, offers a picture of how risky it is to get a lift from a teenage driver. Indeed, a 16-year-old driver with three or more passengers is three times as likely to have a fatal(致命)accident as a teenager driving alone. By contrast, the risk of death for drivers between 30 and 59 decreases with each additional passenger. The author also found that the death rates for teenage drivers increased dramatically after 10 p. m.,and especially after midnight. With passengers in the car,the driver was even more likely to die in a late night accident. Robert Foss, a scientist at the University of North Carolina Highway Safety Research Center, says the higher death rates for teenage drivers have less to do with 'really stupid behavior' than with just a lack of driving experience. 'The basic thing, 'he says, 'is that adults who are responsible for issuing(发放) licenses fail to recognize how skilled a task driving is. ' Both he and the author of the study believe that the way to reduce the harm is to have so-called graduated licensing systems, in which getting a license is a slower process. A graduated license requires that a teenager first prove himself capable of driving in the presence of an adult, followed by a period of driving at night with a limited number of passengers before graduating to get a full driving license. Graduated licensing systems have reduced teenage driver crashes, according to recent studies. About half of the states now have some sort of graduated licensing system in place, but only 10 of those states have number limitation on passengers. California is the strictest, with a new driver prohibited from carrying any passenger under 20 for the first six months. 76.Which of the following situations is most dangerous according to the passage? A. Adults giving a lift to teenagers on the highway after 10 p. m. B. A teenager driving after midnight with passengers in the car. C. Adults driving with three or more teenage passengers late at night. D. A teenager getting a lift from a stranger on the highway at midnight. 77.According to Robert Foss, the high death rate of teenage drivers is mainly due to_______. A. their frequent driving at night         B. their lack of driving experience C. their improper way of driving         D. their driving with passengers 78.Which of the following statements is true according to Paragraph 3 ? A. Teenagers should spend more time learning to drive. B. Driving is a skill too difficult for teenagers to learn. C. Teenagers should be limited in taking driving lessons. D. People issuing license are partly responsible for the accidents. 79.A suggested measure to be taken to reduce teenagers'driving accidents is that_______ A. driving in the presence of an adult should be made a rule. B. they should be forbidden to take on passengers C. they should not be allowed to drive after 10 p. m. D. the licensing systems should be improved 80.The present situation in about half of the states is that the graduated licensing system_______. A. is under discussion              B. is about to be set up C. has been put into effect                 D. has been perfected