Chronic insomnia is a major public health problem. And too many people are using__1__ therapies，even while there are a few treatments that do work. Millions of Americans __2__awake at night counting sheep or have a stiff drink or __3__an pill，hoping it will make them sleepy.__4__ experts agree all that self-medicating is a bad idea，and the causes of chronic insomnia remain__5__. Almost a third of adults have trouble sleeping，and about 10 percent have__6__ of daytime impairment that signal true insomnia. But __7__the complaints，scientists know surprisingly little about what causes chronic insomnia，its health consequences and how best to treat it，a panel of specialists __8__together by the National Institutes of Health concluded Wednesday. The panel called__9__a broad range of research into insomnia，__10__that if scientists understood its __11__causes，they could develop better treatments. Most，but not all，insomnia is thought to __12__other health problems，from arthritis and depression to cardiovascular disease. The question often is whether the insomnia came first or was a result of the other diseases and how trouble sleeping in__13__complicates those other problems. Other diseases __14__，the risk of insomnia seems to increase with age and to be more __15__among women，especially after their 50s. Smoking，caffeine and numerous __16__drugs also affect sleep. The NIH is spending about $200 million this year on sleep-related research，some__17__to specific disorders and others __18__the underlying scientific laws that control the nervous system of sleep. The agency was__19__the panel‘s review before deciding what additional work should be__20__ at insomnia.

1. [A] unproven [B] unknown [C] improper [D] imperative

2. [A] fall [B] lie [C] seem [D] become

3. [A] prescribe [B] pop [C] abuse [D] experiment

4. [A] And [B] Though [C] Thus [D] But

5. [A] peculiar [B] anonymous [C] mysterious [D] unexpected

6. [A] signals [B] symptoms [C] signs [D] symbols

7. [A] in addition to[B] except for [C] owing to [D] for all

8. [A] pulled [B] collected [C] brought [D] drawn

9. [A] on [B] for [C] up [D] in

10. [A] noting [B] notifying [C] nosing [D] nominating

11. [A] undertaking[B] underlining [C] underlying [D] undermining

12. [A] cause [B] accompany [C] follow [D] attend

13. [A] short [B] case [C] essence [D] turn

14. [A] inside [B] outside [C] aside [D] besides

15. [A] common [B] popular [C] frequent [D] regular

16. [A] conscription[B] description [C] subscription[D] prescription

17. [A] aimed [B] targeted [C] designated [D] designed

18. [A] examining [B] inspecting [C] verifying [D] assessing

19. [A] conducting [B] awaiting [C] receiving [D] considering

20. [A] assigned [B] charged [C] directed [D] attended

总体分析本文主要介绍了对失眠的研究工作。文章第一段指出慢性失眠是一个重要的公共健康问题，但其致病原因仍是个迷。第二段介绍了(美)全国卫生研究所一个专家小组的结论，该小组呼吁对失眠进行广泛的研究。第三段讨论了失眠与其他因素，如疾病、年龄、药物等的关系。第四段介绍了(美)全国卫生研究所对失眠正在进行的研究情况。

全文翻译：慢性失眠是一个主要的公共健康问题。而且，太多人正使用未经验证的治疗方法，尽管有些方法确实是有效的。上百万的美国人夜里睡不着觉，躺着数羔羊、喝杯烈酒或吞个药片，希望这会使他们产生困意。然而，专家们一致认为，自作主张乱吃药并不是解决失眠的好方法，导致慢性失眠的原因目前还是一个谜。

几乎有1/3的成年人存在睡眠障碍，而且大约10%的人有白天功能减退的症状，这些症状表明他们确实患上了失眠症。但是，一个由(美)全国卫生研究所召集的专家小组在周三得出这样的结论：尽管(社会上关于长期失眠的)抱怨很多，但科学家们对长期失眠的原因，它对健康的影响以及如何有效地治疗都知之甚少。该专家小组呼吁对失眠症进行广泛研究，指出如果科学家们了解了失眠的潜在原因，他们可能会发现更好的治疗方法。

很多，但不是所有的失眠症被认为伴随着其他健康问题产生，从关节炎、抑郁到心血管疾病。而问题通常是不知道是先产生失眠，还是失眠是其他疾病的结果，以及失眠如何又使其他问题变得更加复杂。撇开其他疾病不说，失眠的可能性随着年龄的增加而增加，而且在妇女中更加普遍，尤其是50岁以后。吸烟、咖啡因及众多的处方药也影响睡眠。

(美)全国卫生研究所今年要花大约2000亿美元用于睡眠的相关研究，其中一些以特定的(睡眠)紊乱为目标，另外一些观察控制睡眠神经系统的潜在科学规律。该机构正等待专家小组的评论以决定对失眠进行的下一步研究工作。

答案：1.A 2.B 3.B 4.D 5.C 6.B 7.D 8.C 9.B 10.A 11.C 12.B 13.D 14.C 15.A 16.D 17.B 18.A 19.B 20.C