Ifyouwanttoincreaseyouroddsofhavingalong
If you want to increase your odds of having a long and lively lifetime, scientists say, work on getting an average of seven or eight hours of sleep a night. If you get only six hours or less, you stand a 70 percent chance of dying before your time. Scientists are finding that if you don’’t get enough sleep, you are putting yourself at increased risk of heart trouble, digestive disease, or a serious, even fatal (致命的) accident. When tired, your sight, hearing, and attention are slow to alert you to dangers--and once you are aware of them, your reactions are also slow. H.Craig Heller--a professor of biology at Stanford University--is one of a small army of scientists studying the reasons why many people can’’ t sleep and wake refreshed, why the brain puts you to sleep, and why lack of sleep causes such powerful effects. Heller notes that most major accidents have occurred in the early morning, when workers probably were still sleepy from deficient (不足的) sleep. He includes the explosion at the nuclear power plant atChernobyl in Ukraine, the release of poisonous gas atBhopal, India and the nuclear accident at Three Mile Island in Pennsylvani
A、 Scientists estimate that more than 100 millionAmericans have sleep troubles of some kinD、Getting too little sleep heads the list.As many as oneAmerican in five gets fewer than six hours of sleep a night. Some people can get along on six hours, but most of us need between seven and eight--and children and young adults need up to 10 hours.As we age, it becomes more difficult to get enough sleep.At any age, however, we all can pile up a sleep deficit that eventual ly will force us to fall asleep--whether we’’ re ready or not. Which of the following statements is NOT true according to the passage
A、Getting too little sleep is the commonest sleep trouble with mostAmericans who have sleep trouble.
B.At least twenty percent ofAmericans don’’ t have enough sleep every night.
C.Our brains will force us to sleep when we have piled up too large a sleep deficit
D.Seven or eight hours of sleep every night is enough for people of different ages.