Questions 21 to 25 are based on the following passage.

　　A recent study, 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 accident as a teenager driving alone, By contrast, the risk of death for drivers between 30 and 59 decreases with each additional passenger.

　　The authors 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 issue.” Be says, “is that adults who are responsible for issuing licenses fail to recognize how complex and skilled a task driving is.”

　　Both he and the author of the study believe that the way to mitigate (使…缓解) the problem is to have states institute so-called graduated licensing systems, in which getting a license is a multistage 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 with night of passenger restrictions, before graduating to full driving privileges.

　　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 restrictions on passengers, California is the strictest, with a novice (新手) driver prohibited from carrying any passenger under 20 (without the presence of an adult over 25) for the first six months.

　　21. 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.(B)

　　22. According to Robert Foss. The high death rate of teenage drivers is mainly due to ________.

　　A) their frequent driving at night

　　B) their improper way of driving

　　C) their lack of driving experience

　　D) their driving with passengers(C)

　　23. According to Paragraph 3. which of the following statements is TRUE?

　　A) Teenagers should spend more time learning to drive.

　　B) Driving is a skill too complicated for teenagers to learn.

　　C) Restrictions should be imposed on teenagers applying to take driving lessons.

　　D) The licensing authorities are partly responsible for teenagers’ driving accidents.(D)

　　24. A suggested measure to be taken to reduce teenagers’ driving accidents is that ________.