In a field where scientists have spent decades focused on genetics and the buildup of damaged protein fragments called beta-amyloid as causes of the disease,now many experts agree that air pollution plays a major role. For the most common form of Alzheimer's,known as late-onset disease,researchers now estimate that at least 40 and as much as 65 percent of the risk involves nongenetic influences such as lifestyle and harmful environmental exposure.

【思考题】

Traditional views on Alzheimer's agreed that （   ）

A.it could be mainly attributed to genetics

B.it had a close relation to lifestyle choices

C.it was triggered by nongenetic factors

D.it was related to the harmful air pollution 

【词汇突破】

buildup    沉积

protein fragments   蛋白质片段

beta-amyloid   β-淀粉样蛋白

Alzheimer's    阿尔茨海默氏症

late-onset disease  晚发性亚型

亚型=类型=form 

nongenetic   非基因的

involve   涉及到

【句子解析】

第1句：

In a field where scientists have spent decades focused on genetics and the buildup of damaged protein fragments called beta-amyloid as causes of the disease （传统的观点），now many experts agree that air pollution plays a major role.

在这一领域，科学家数十年来一直专注于遗传学，并将被称为β-淀粉样蛋白的受损蛋白质片段的沉淀视作疾病成因，现在许多专家都同意空气污染起着重要作用。

注意：这里的疾病disease 就包括后文的Alzheimer's 这就是阅读的相关性原则。

第2句：

For the most common form of Alzheimer's, known as late-onset disease,researchers now（现在的观点）estimate that at least 40 and as much as 65 percent of the risk involves nongenetic influences such as lifestyle and harmful environmental exposure.

研究人员现在估计，对于常见的阿尔茨海默氏症亚型，即晚发性亚型，风险因素中至少40%到65%涉及非遗传影响，如生活方式和有害的环境暴露。

【思考题解析】

Traditional views on Alzheimer's agreed that （  ）

A.it could be mainly attributed to genetics 它可能主要归因基因

A项正确

B.it had a close relation to lifestyle choices  它与生活方式的选择密切相关

B项错误

C.it was triggered by nongenetic factors 它是由非基因因素引起的

C项错误

D.it was proven to be related to pollution 它被证明与污染有关

D项错误

【文章背景】

The Role of Air Pollution 

空气污染的角色

背景：谈到空气污染之害，雾霾和有毒粉尘会损伤心肺功能已是共识。但空气污染与老年痴呆的关系直到最近几年才开始真正获得学者们的关注。2018年，一项针对墨西哥城（1992年被联合国宣布为世界上污染极严重的城市）居民的研究发现，年纪仅在30到40岁的中年居民脑中已出现斑块病变，而从年纪上来说，通常要几十年后才能察觉到任何疾病的症状。不仅是在墨西哥城，许多学者针对不同地域人群的众多研究证实了同一个结论，在特定的空气污染物中的暴露和一些神经退行性疾病相关性极强，其中就包括阿尔茨海默氏症。有毒的空气微粒可经由肺、鼻进入大脑，空气污染物的暴露史与记忆丧失等痴呆症状直接相关！