Chronic insomnia is a major public health problem. And too many people are using 【B1】______ therapies, even while there are a few treatments that do work. Millions of Americans 【B2】______ awake at night counting sheep or have a stiff drink or 【B3】______ an pill, hoping it will make them sleepy. 【B4】______ experts agree all that self-medicating is a bad idea, and the causes of chronic insomnia remain【B5】______. Almost a third of adults have trouble sleeping, and about 10 percent have 【B6】______ of daytime impairment that signal true insomnia. But【B7】______the complaints, scientists know surprisingly little about what causes chronic insomnia, its health consequences and how best to treat it, a panel of specialists【B8】______together by the National Institutes of Health concluded Wednesday. The panel called 【B9】______ a broad range of research into insomnia,【B10】______that if scientists understood its【B11】______causes, they could develop better treatments. Most, but not all, insomnia is thought to【B12】______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【B13】______complicates those other problems. Other diseases【B14】______, the risk of insomnia seems to increase with age and to be more【B15】______among women, especially after their 50s. Smoking, caffeine and numerous【B16】______drugs also affect sleep. The NIH is spending about $200 million this year on sleep-related research, some【B17】______to specific disorders and others【B18】______the underlying scientific laws that control the nervous system of sleep. The agency was【B19】______the pane' s review before deciding what additional work should be【B20】______at insomnia.

【正确答案】 D

【答案解析】解析：考查逻辑关系。前文说“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”。后文指出“自作主张乱吃药并不是解决失眠的好方法”，可见前后是转折关系，故选D．But“但是”。And“和”；Though“尽管”；Thus“因此”，均不符合题意。

【正确答案】 D

【答案解析】解析：考查短语辨析。此空所在句子意为：______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。于是逻辑关系为让步。因此选D．for all“尽管，虽然”。in addition to“此外”；except for“除…之外”；owing to“由于”，均不符合题意。

【正确答案】 B

【答案解析】解析：考查动词短语辨析。call on意为“拜访(某人)；叫；号召；要求”；call for意为“去接(某人)；去取(某物)；需要；要求”；call up意为“给…打电话”；call in意为“叫(某人)进来，来访”，比较四个短语，只有call for符合题意。因此B．for为正确答案。

【正确答案】 C

【答案解析】解析：考查词语辨析。此空所在句子意为：指出如果科学家们了解了失眠的______原因，此处所选动词分词是用来形容causes的，故C．underlying“潜在的，含蓄的”符合题意。undertaking为名词，意为“事业，企业，承诺”；underlining与undermining均为动词转换的现在分词，其中underline意为“在…下面划线，加强，强调”，undermine意为“破坏，削弱”，均不符合题意。

【正确答案】 B

【答案解析】解析：考查动词辨析。此空所在句子的意思为“很多但不是所有的失眠症被认为______其他健康问题产生”，下文列举了具体的疾病，且由下文可知，失眠与其他健康问题的因果关系及出现先后顺序还不清楚。因此，此空选B．accompany“伴随”。cause“引起”；follow“跟着”；attend“出席，参加”，均不符合题意。

【正确答案】 D

【答案解析】解析：考查名词辨析。此空所在句子意为：吸烟、咖啡因及众多的______也影响睡眠。第一段末提到“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”，因此答案应为D．prescription“处方”。conscription“征兵，征用”；description“描写”；subscription“订阅费，捐款”，均不符合题意。

【正确答案】 B

【答案解析】解析：考查动词辨析。此空所在句子意为：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______。因此，选B．targeted“把…作为目标”。aimed后常接at，表示“旨在，致力于”；designated“指出，指明”；designed“设计，计划”，常见用法为be designed to do sth．，均不符合题意。

【正确答案】 A

【答案解析】解析：考查动词辨析。此空所在句子意为：其中一些以特定的(睡眠)紊乱为目标，另外一些控制睡眠神经系统的潜在科学规律。A．examining“检查”，多用于医学方面的检查，故符合题意。inspecting“检查”，多用于领导视察；verifying“核实，判定”；assessing“评估”，均不符合题意。