问题 问答题

(46) It is known that the brain shrinks as the body ages, but the effects on mental ability are different from person to person. Interestingly, in a study of elderly men and women, those who had more education actually had more brain shrinkage.
"That may seem like bad news," said study author Dr. Edward Coffey, a professor of psychiatry and of neurology at Henry Ford Health System in Detroit. (47) However, he explained, the finding suggests that education allows people to withstand more brain tissue loss before their mental functioning begins to break down.
The study, published in the July issue of Neurology, is the first to provide biological evidence to support a concept called the "reserve" hypothesis, according to the researchers. In recent years, investigators have developed the idea that people who are more educated have greater cognitive reserves to draw upon as the brain ages; in essence, they have more brain tissue to spare.
(48) Examining brain scans of 320 healthy men and women aged 66 to 90, researchers found that for each year of education the subjects had, there was greater shrink age of the outer layer of the brain known as the cortex. Yet on tests of cognition and memory, all participants scored in the range indicating normal.
"Everyone has some degree of brain shrinkage," Coffey said. "People lose (on average) 2.5 percent per decade starting in adulthood."
There is, however, a "remarkable range "of shrinkage among people who show no signs of mental decline, Coffey noted. Overall health, he said, accounts for some differences in brain size. Alcohol or drug use, as well as medical conditions such as diabetes and high blood pressure, contribute to brain tissue loss throughout adulthood.
In the absence of such medical conditions, Coffey said, education level helps explain the range of brain shrinkage exhibited among the mentally-fit elderly. The more-educated can withstand greater loss.
(49) Coffey and colleagues gauged shrinkage of the cortex by measuring the cerebrospinal fluid surrounding the brain. The greater the amount of fluid, the greater the cortical shrinkage.
Controlling for the health factors that contribute to brain injury, the researchers found that education was related to the severity of brain shrinkage. For each year of education from first grade on, subjects had an average of 1.77 milliliters 11 more cerebrospinal fluid around the brain.
Just how education might affect brain cells is unknown. (50) In their report, the researchers speculated that in people with more education, certain brain structures deeper than the cortex may stay intact to compensate for cortical shrinkage.

答案

参考答案:然而,他解释说,这项研究成果表明的是,接受过教育的人在大脑功能开始崩溃之前更能经受得住大脑组织的丧失。

解析:[结构分析]
句子的框架是However,he explained,the finding suggests that education allows people to withstand…before their mental functioning begins to break down。he explained是插入语。that引导宾语从句。在此从句中包含了一个由before引导的 时间状语从句;suggest这里意思是“表明,显示”,break down翻译为“崩溃”。

判断题
单项选择题

纳西族主要聚居于云南省丽江纳西族自治县,其余分布在维西、中甸、宁蒗、德钦和四川盐边、盐源、木里及西藏的芝康等县。纳西族原是中国西北古羌人的一个支系,大约在公元三世纪迁徙到丽江地区定居下来。
早在一千多年前,纳西族创造了这个民族的珍贵文化遗产——东巴象形文字和用这种文字写成的东巴经。东巴象形文字,纳西语叫做“森究鲁究”,被中外学者誉为“纳西族古代的百科全书”。1957年设计了拉丁字母形式的文字。
纳西族主要从事农业、畜牧业,手工业也有发展,“丽江马”闻名全国。现已有机修、采煤、发电、化肥、电机、轻工等中小企业。金沙江两岸出产多种药材和特产。纳西族普遍信奉东巴教,一部分人信仰喇嘛教。
纳西族以农历记年。主要节日有春节、清明节、端午节、中秋节、火把节、“三月龙王庙会”、“七月骡马会”等。不少节日,如春节、清明、端午、中秋等均与当地汉族大致相同。春节是最大的传统节日,并且伴有许多祭祀活动。春节时演奏道庙音乐,即人们常说的“纳西古乐”。纳西族男子的服装大体与汉族相同。纳西族女子的衣服五颜六色,你应该特别留意——肥肥大大,外面还罩着一件厚厚的羊皮披肩,肩膀的两边有两个大圆布圈,代表着日月,披肩上面的黑色代表黑夜,下面的白色代表白天,中问还绣着精美的七星,所以这种衣服有一个好听的名字,叫“披星戴月”,象征着纳西族妇女的勤劳。

文中提到的纳西古乐是:

A.春节演奏的道庙音乐

B.纳西族的流行音乐

C.纳西族的婚礼音乐

D.纳西族的现代音乐