Sleep deficiency affects many Americans: CDC

    LOS ANGELES, March 3 (Xinhua) -- More and more American adults are suffering from a decline in overall sleep duration(持续时间), the U.S. Centers for Disease Control and Prevention (CDC) (疾病防治中心)said on Thursday.
    It's recommended that adults should sleep seven to nine hours a night to maintain good health, but more than one-third of Americans do not meet that requirement, according to the CDC.
    Insufficient¹ sleep poses a long-term heath threat and impairs² work performance and the ability to drive safely, the CDC said.
    Chronic³ sleep loss also is associated with obesity⁴, increased risk of death and other health problems, according to the CDC.
    "Over the last 20 years there has been a decline in overall sleep duration in adults," said Lela McKnight-Eily, a clinical psychologist and epidemiologist at the CDC's National Center for Chronic Disease Prevention.
    "Within our culture there seems to be a belief that sleep isn't a part of overall essential health," she said.
    McKnight-Eily and her colleagues studied the sleep habits of 74,571 adults in 12 states, 35.3 percent reported sleeping less than seven hours.
    In addition, 48 percent reported snoring, 37.9 percent said they fell asleep at least once during the day the previous month and 4.7 percent admitted to falling asleep at the wheel at least once.
    Drowsiness⁵ or nodding off while driving accounts for 1,550 deaths and 40,000 injuries a year, according to the U.S. Department of Transportation.
    To get enough sleep, Americans have to change lifestyle habits, including longer workdays and late nights on the computer, McKnight-Eily said, noting that too much screen time paring away much-needed sleep time.(本文由在线英语听力室整理编辑)

1 insufficient   

adj.(for，of)不足的，不够的

参考例句：

• There was insufficient evidence to convict him.没有足够证据给他定罪。
• In their day scientific knowledge was insufficient to settle the matter.在他们的时代，科学知识还不能足以解决这些问题。

2 impairs   

v.损害，削弱( impair的第三人称单数 )

参考例句：

• Smoking impairs our health. 吸烟会损害我们的健康。 来自《简明英汉词典》
• Almost anything that impairs liver function can cause hepatitis. 任何有损于肝功能的因素，几乎都会引起肝炎。 来自辞典例句

3 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

4 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。

5 drowsiness   

n.睡意；嗜睡

参考例句：

• A feeling of drowsiness crept over him. 一种昏昏欲睡的感觉逐渐袭扰着他。 来自《简明英汉词典》
• This decision reached, he finally felt a placid drowsiness steal over him. 想到这，来了一点平安的睡意。 来自汉英文学 - 骆驼祥子