According to a report from the Harvard School of Public Health, many everyday products, including some bug sprays and cleaning fluids, could lead to an increased risk of brain and behavioral disorders in children. The developing brain, the report says, is particularly (36)_____ to the toxic effects of certain chemicals these products may contain, and the damage they cause can be (37)_____.

    The official policy, however, is still evolving. Health and environmental (38)_____ have long urged U.S. government agencies to (39)_____ the use of some of the 11 chemicals the report cites and called for more studies on their long-term effects. In 2001, for example, the Environmental Protection Agency (40)_____ the type and amount of lead that could be present in paint and soil in homes and child-care (41)_____, after concerns were raised about lead poisoning. The agency is now (42)_____ the toxic effects of some of the chemicals in the latest report.

    But the threshold for regulation is high. Because children’s brain and behavioral disorders, like hyperactivity and lower grades, can also be linked to social and genetic factors, it’s tough to pin them on exposure to specific chemicals with solid (43)_____ evidence, which is what the EPA requires. Even the Harvard study did not prove a direct (44)_____ but noted strong associations between exposure and risk of behavioral issues.

    Nonetheless, it’s smart to (45)_____ caution. While it may be impossible to prevent kids from drinking tap water that may contain trace amounts of chemicals, keeping kids away from lawns recently sprayed with chemicals and freshly dry-cleaned clothes can’t hurt.

动词：exercise行使，运用；investigating调查，研究；overwhelmed压倒，击败，淹没；restricted限制，限定；simulating模拟，模仿，假装；tighten使变紧，加强控制

形容词：compact紧密的，紧凑的；permanent永久的；statistical统计上的，统计学上的：vulnerable 脆弱的，易受伤害的．

36．vulnerable。此处应填入形容词vulnerable，本句含义为“孩子们正在发育的大脑易受伤害”，be vulnerable to为固定搭配，表示“易受……的伤害”．故选O.vulnerable“脆弱的，易受伤害的”。

37．permanent。可填形容词或名词作表语。本句含义为“所造成的危害可能是永久性的”。所以此处应填入形容词permanent一故选J.permanent“永久的”。

38．advocates。此处应填入复数形式的名词，作句子的主语、，本句主语所发出的动作是“敦促政府部门做某事”，故选A)advocates。

39．tighten。应填入及物动词的原形，上文提到官方政策还在制定中，而健康及环保人士已经做出努力，下文提到“报告中提及ll种化学品的使用”，故此处应填人tighten，本句含义为“健康及环保政策的拥护者们敦促政府部门加强对报告中提及的ll种化学品的管制”。故选N)tighten“使变紧，加强控制”。

40．restricted。应填入动词的过去式。综合上下文考虑，本句含义应为“环保部门限制了铅使用的种类和数量”。

41．facilities。空格处应填入名词，本句含义为“环保部门限制了存留在家居环境中的涂料、土壤及儿童保育器械上所使用铅的种类和数量”。故选E.facilities“设施，设备”。

42．investigating。该空格位于句子的谓语动词位置，句中明确出现了时间状语now，故谓语动词应使用现在进行时，本句含义为“目前这个机构正在研究最新的报告中所提及的一些化学品的毒性”。

43．statistical。空格处应填入形容词，与solid一起修饰名词evidence。根据常识可知，统计学数据对于政策制定关系很大，故此处应填入statistical。

44．correlation。应填入可数名词的单数形式。此处表达的意义为“暴露于有害的化学物质之下与患行为方面疾病风险之间存在直接相关性”。故选C.correlation“相关，关联”。

45．exercise。应填入动词原形，且该动词还能与caution进行搭配，从上下文语境可知，本句含义为“采取小心谨慎的措施总是明智的选择”， 故选D)exercise“行使，运用”。