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 __26__ to the toxic effects of certain chemicals these products may contain, and the damage they cause can be __27__ .
The official policy, however, is still evolving. Health and environmental __28__ have long urged US government agencies to __29__ 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 30 the type and amount of lead that could be present in paint and soil in homes and child-care 31 , after concerns were raised about lead poisoning. The agency is now _32__ 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 __33__ evidence, which is what the EPA requires. Even the Harvard study did not prove a direct 34 but noted strong associations between exposure and risk of behavioral issues.
Nonetheless, it’s smart to __35__ 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.
A) advocates
B) compact
C) correlation
D) exercise
E) facilities
F) interaction
G) investigating
H) overwhelmed
I) particles
J) permanent
K) restricted
L) simulating
M) statistical
N) tighten
O) vulnerable
答案解析：
26. O根据空格前的系动词 is 和空格后的介词 to，可知此处需要一个形容词。句意是，发育中的大脑对这些产品中某些化学物质的毒性作用尤其____”。结合后文提到的 damage (伤害)”，可以推断大脑是易受伤害的”。vulnerable (易受伤害的，脆弱的) 符合句意。所以选 O) vulnerable。
27. J根据空格前的情态动词 can be 和空格后的名词 damage，可知此处需要一个形容词来修饰 damage。句意是，它们造成的伤害可能是____的”。结合常识和后文提到的对儿童大脑的长期影响”，可以推断这种伤害可能是永久的”。permanent (永久的，持久的) 符合句意。所以选 J) permanent。
28. A根据空格前的并列连词 and 和空格后的谓语动词 have urged，可知此处需要一个与 health and environmental”并列的名词，指代某类人或组织。句意是，健康和环境的____们长期以来一直敦促...”。advocates (倡导者，拥护者) 符合句意，指环保倡导者。所以选 A) advocates。
29. N根据空格前的动词不定式 to 和空格后的名词 the use，可知此处需要一个动词原形。句意是，...敦促美国政府机构____报告中提到的11种化学品中某些的使用”。结合后文关于限制铅含量的例子，可以推断是收紧、限制”使用。tighten (收紧，加强) 符合句意，常与 regulations, rules, use 等搭配。所以选 N) tighten。
30. K根据空格前的主语 The Environmental Protection Agency 和空格后的宾语 the type and amount of lead，可知此处需要一个动词的过去式。句意是，环保局____了油漆和土壤中铅的类型和含量”。结合语境，环保局采取的措施应是限制”。restricted (限制) 符合句意。所以选 K) restricted。
31. E根据空格前的名词 child-care，可知此处需要一个名词，与 homes (家庭) 并列，构成 homes and child-care ____”。句意是，家庭和儿童保育____中的油漆和土壤”。facilities (设施，场所) 符合句意，指托儿所等机构。所以选 E) facilities。
32. G根据空格前的 is now 和空格后的宾语 the toxic effects，可知此处需要一个动词的现在分词形式，构成现在进行时。句意是，该机构现在正在____最新报告中一些化学物质的毒性作用”。根据语境，环保局在研究这些化学物质。investigating (调查，研究) 符合句意。所以选 G) investigating。
33. M根据空格前的形容词 solid 和空格后的名词 evidence，可知此处需要一个形容词来修饰 evidence (证据)。句意是，很难将这些问题归咎于特定化学物质的接触，因为缺乏确凿的____证据”。后文提到哈佛研究没有证明直接因果关系，只证明了强关联”，这属于统计学范畴。statistical (统计的) 符合句意。所以选 M) statistical。
34. C根据空格前的形容词 direct 和空格后的 but，可知此处需要一个名词。句意是，哈佛研究没有证明直接的____，但指出了接触和行为问题之间的强关联”。根据 but”的转折，前面应该是比 association (关联) 更强的因果关系”，但研究未能证明，所以证明的是关联”本身。correlation (相关性，关联) 符合句意。所以选 C) correlation。
35. D根据空格后的名词 caution，可知此处需要一个动词。句意是，无论如何，____谨慎是明智的”。exercise caution 是一个固定搭配，意为保持谨慎，采取谨慎态度”。所以选 D) exercise。
