Sleep Loss and Its Effects Mental fatigue can be as threatening as a heart attack. Recent evidence indicates that sleepiness is a leading cause of traffic and industrial accidents. “Human error causes between 60% and 90% of all workplace accidents, depending on the type of job,” observes biological psychologist David Dinges of the University of Pennsylvania. “And inadequate sleep is a major factor in human error” , other research suggests that sleep loss contributes to everything from drug abuse to poor grades in school. A typical adult needs about eight hours of shut-eye a night to function effectively. By that standard, million of Americans are for a long time sleep deprived, trying to get by on six hours or even less. In many household cheating on sleep has become an unconscious and harmful habit. “In its mid form, it s watching Ted Koppel and going to bed late and then getting up early to get to the gym,” says Cornell s Pollak. In extreme cases people stay up most of the night, seeing how little sleep will keep them going. They try to compensate by sleeping late on weekends, but that makes up for only part of the shortfall. Over the months and years, some researchers believe, the imbalance builds up and the effects accumulate. “Most Americans no longer know what it feels like to the fully alert,” contends Dr. William Dement, director of Stanford University s Sleep Center. They go through the day in a sort of twilight zone. the eyes may be wade open, but the brain is partly shut down. Single parent Dianna Bennett, 43, works as a nurse at a correctional facility in Gardner, Mass. To be able to spend time with her three children during the day, she works the night shift, a schedule that usually allows her no more than four hours of sleep, “My kids tell me I am always tired.” She says. Amy Schwartzman, 35, a law student at Yale University, gets up at 9 a.m. and then, she attends classes and simulated court and work as a research assistant, often does not get home until 10 p.m. Nights of throwing into bed at 3 a.m. makes her feel “as if my brain isn t moving as quickly as it should be.” Noting that the circles under her eyes keep getting darker, “My mother told me I look like a raccoon.” Says Schwartzman. 31. Sleep loss contributes to everything EXCEPT______. A. drug abuse B. poor school grades C. work effect D. accidents 32. According to the passage, on weekends some people always ______. A. go to bed百考试题－全国最大教育类网站(100test.com) B. go to bed early C. get up late D. get up early 33. Because of sleep loss, most American ______. A. have wide open eyes B. are not fully alert C. try to sleep more D. live in the twilight zone 34. Though not stated, the author implies that ______. A. American drug abuse is connected with loss of sheep B. American students poor grades result from lack of sleep C. Adequate sleep is necessary for people s health D. Accidents in the states could be reduced by more sleep 35. In his passage, which of the following is NOT mentioned by the author? A. How interesting American night life is. B. How busy some Americans are.来源：考试大 C. Some Americans attitude toward sleep. D. People should have more sleep.