A. 9 million people in America have a weight problem

　　B. not enough sleep contributes to a gain in weight

　　C. sixth graders need more sleep than third graders

　　D. lack of sleep has become the most deadly killer

　　解析：选B。考查细节理解。本文阐述了睡眠与青少年肥胖之间的关系。第二段说，一项新研究发现，睡眠太少的小学生更容易发胖，美国有900万6岁以上的孩子患肥胖症。从文章的叙述判断选B。

　　2. The statement "Which came first，the chicken or the egg？" suggests that ________.

　　A. scientists are sure about the causes of children's obesity

　　B. it's easy to decide the cause and effect of this problem

　　C. scientists are still confused about the cause and effect of the problem

　　D. you'll develop obesity if you eat chicken and eggs

　　解析：选C。考查推理判断。第三段画线句子后面又说"换句话说，究竟是发胖的孩子有睡眠问题，还是睡眠减少导致了体重的增加，这还不清楚。"也就是说，发胖与睡眠减少这两者哪个是原因，哪个是结果，科学家们也还不知道。

　　3. Recent studies show that a child's weight is influenced by the ________.

　　A. amount of sleep B. parents' attitude to him

　　C. race or gender D. performance in school

　　解析：选A。考查推理判断。第三段说，以往的研究表明睡眠不足与发胖有联系，但科学家不知道哪个是原因，哪个是结果；第五段开头提到研究的结论：睡眠似乎是主要因素。也就是说该研究表明，孩子的体重受睡眠时间长短的影响。

　　4. The underlined part in the last paragraph most probably means something ________.

　　A. acceptable　　　　　　　　B. understandable

　　C. reliable D. unreasonable

　　解析：选D。考查词义猜测。后文说"但他们的研究结论却很有说服力。"由此可推知，画线部分的含义应该是D；他们本来希望这种说法是错误的，可是研究结论却让人不得不相信睡眠和肥胖有关。

　　B

　　(2010年黄冈中学期中测试)Doomed beauties such as Cleopata and Manilyn Monroe were far from alone in their misery. Very attractive people tend to form partnerships that are less stable and satisfying than those enjoyed by plain_Janes .

　　According to the research by Dr John Blaine of the University of Southern California, relationships between people whose professions largely depend on their appearance, such as models or actors, tend to end much faster than those between lawyers, doctors and students.

　　Blaine said the beautiful felt different from children. They are treated as special, which may create both arrogance (傲慢)and insecurity. All too often, beauty can be used as an alternative to education. Often they are pushed out of their class or town, told to go off and make their fortune in Hollywood or London and, when the majority fail, they have few talents to make a living.

　　Blaine added that beautiful people score poorly on the "big five"-the key factors American experts consider when helping distressed couples. These are neuroticism(神经过敏)，including anger and anxiety; extroversion(性格外向)；openness to new experiences; agreeableness; conscientiousness, and sticking by agreements they have made. Attractive people often see no reason to try to change until their looks start to fade.

　　Krista Sutherlanf, of the University of California Los Angeles, said partnerships that appeared to be perfect from the outside, such as the former "dream teams" of Nicole Kidman and Tom Cruise or Hugh Grant and Elizabeth Hurley, where backgrounds and aspirations(抱负) are often shared ，did not necessarily lead to happiness.

　　【解题导语】　本文为议论文，作者论证了这样一个观点：美女并不幸福。

　　5. What can we infer from the first sentence of the passage?

A. Beautiful women always felt lonely.