【正确答案】 A

【答案解析】[听力原文]26-30 There are new findings that people with inadequate sleep are likely to gain weight. Researchers say a lack of sleep can produce hormonal changes that increase feelings of hunger. In one study, researchers from Stanford University in California and the University of Wisconsin examined information on more than one thousand people. The people had taken part in a long-term study of sleep disorders. Some people slept less than five hours a night. They had fifteen percent higher blood levels of a hormone called ghrelin than people who slept eight hours. And they had fifteen percent less of the hormone leptin. Experts say ghrelin helps make people feel hungry; leptin makes you feel full. The results were not affected by how much people exercised. People who are awake longer have more time to burn energy. But the researchers say loss of sleep may increase hunger especially for high-calorie foods, so people gain weight. Researchers found that the best amount of sleep for weight control is seven-point-seven hours a night. Researchers at the University of Chicago did a smaller study. They found that people who slept just four hours a night for two nights had an eighteen percent reduction in leptin. And they had a twenty-eight percent increase in ghrelin. The young men in that study also appeared to want more sweet and starchy foods. Researchers from Columbia University in New York did a third study. They found that people who got less than four hours of sleep a night were seventy-three percent more likely to be overweight. This was compared to people with seven to nine hours of sleep. The researchers say that for survival, the body may be designed to store more fat during times with less sleep. [分析] 归纳总结。 题干：根据文章，美国有几所大学参与了该项研究?原文提到的大学有： Stanford University，University of Wisconsin，University of Chicago，Columbia University。所以选a。

【正确答案】 B

【答案解析】[分析] 原因结果。 题干：为什么缺乏睡眠会导致人们变胖?根据原文“Researchers say a lack of sleep can produce hormonal changes that increase feelings of hunger．”，译文为：研究人员说缺乏睡眠会导致荷尔蒙的变化，这种变化会增强饥饿感。所以选c“因为人们缺乏睡眠时会感到饥饿。”。a选项为“因为在清醒的时候燃烧的卡路里较少。”，c选项为“因为他们的荷尔蒙没有改变。”，d选项为“因为人们睡眠不足时不运动。”

【正确答案】 D

【答案解析】[分析] 是非判断。 题干：根据文章，关于第一次研究，哪个说法不正确?a选项为“超过 1,000人参与了该研究。”；根据原文“researchers…examined information on more than one thousand people．”，译文为；研究人员调查了超过1,000人的信息，所以该选项是正确的。b选项为“睡眠较少的人ghrelin的血压高。”，根据原文“Some people slept less…They had fifteen percent higher blood levels of a hormone called ghrelin…”，译文为：睡眠较少的人他们的一种荷尔蒙ghrelin的血压高出15 %。所以该选项是正确的。c选项为“睡眠较多的人leptin的血压高。”，根据原文“…people slept less…they had fifteen percent less of the hormone leptin．”，译文为：睡眠较少的人荷尔蒙leptin低于正常人15%。由此可以推断睡眠多的人该项指标高，所以该选项正确。d选项为“运动量能够影响研究的结果。”，根据原文“The results were not affected by how much people exercised．”，译文为：结果并不受人们运动量的影响。所以该选项是错误的。

【正确答案】 B

【答案解析】[分析] 数字信息。 题干：控制体重需要的最佳睡眠量是多少?根据原文“Researchers found that the best amount of sleep for weight control is seven-point-seven hours a night．”，译文为：研究人员发现控制体重所需要的最佳睡眠量为一个晚上7.7个小时。所以选b。

【正确答案】 C

【答案解析】[分析] 细节信息。 题干：在第三项研究中，两组人做了对比，这两组人分别是?根据原文“They found that people who got less than four hours of sleep a night…This was compared to people with seven to nine hours of sleep．”，译文为：他们发现一个晚上睡眠少于4小时的人……这和睡眠7到9小时的人做了对比。所以选c。