Learning disabilities are very common. They affect perhaps 10 percent of all
children. Four times as many boys as girls have learning disabilities.
Since about 1970，new research has helped brain scientists understand these problems
better. Scientists now know there are many different kinds of learning disabilities and that they are
caused by many different things. There is no longer any question that all learning disabilities result
from differences in the way the brain is organized.
You cannot look at a child and tell if he or she has a learning disability.
There is no outward sign of the disorder. So some researchers began looking at the
brain itself to learn what might be wrong.
In one study，researchers examined the brain of a learning-disabled person，who had died in an accident. They found two unusual things. One involved cells in the left side of
the brain，which control language. These cells normally are white. In the learning-disabled person，howeverthese cells were gray. The researchers also found that many of the nerve cells were not in a
line the way they should have been. The nerve cells were mixed together.
The study was carried out under the guidance of Norman Geschwind，an early
expert on learning disabilities. Doctor Geschwind proposed that learning disabilities resulted mainly
from problems in the left side of the brain. He believed this side of the brain failed to develop
normally. Probably，he said，nerve cells there did not connect as they should. So the brain was like
an electrical device in which the wires were crossed.
Other researchers did not examine brain tissue. Instead，they measured the
brain’s electrical activity and made a map of the electrical signals.
Frank Duffy experimented with this technique at Children’s Hospital Medical
Center in Boston. Doctor Duffy found large differences in the brain activity of normal children
and those with reading problems. The differences appeared throughout the brain. Doctor Duffy
said his research is evidence that reading disabilities involve damage to a wide area of the brain，not just the left side.
1. Scientists found that the brain cells of a learning-disabled person differ
from those of a normal person in .
A. structure and function B. color and function
C. size and arrangement D. color and arrangement
2. Which of the following is NOT mentioned in the passage？
A. Learning disabilities may result from the unknown area of the brain.
B. Learning disabilities may result from damage to a wide area of the brain.
C. Learning disabilities may result from abnormal organization of brain cells.
D. Learning disabilities may result from problems in the left side of the brain.
3. All of the following statements are true EXCEPT that .
A. many factors account for learning disorder
B. a learning-disabled person shows no outward signs
C. reading disabilities are a common problem that affects 10 percent of the population
D. the brain activity of learning-disabled children is different from that of
normal children
4. Doctor Duffy believed that .
A. he found the exact cause of learning disabilities
B. the problem of learning disabilities was not limited to the left side of the brain
C. the problem of learning disabilities resulted from the left side of the brain
D. the problem of learning disabilities did not lie in the left side of the brain
5. According to the passage we can conclude that further researches should be
made .
A. to investigate possible influences on brain development and organization
B. to study how children learn to read and write，and use numbers
C. to help learning-disabled children to develop their intelligence
D. to explore how the left side of the brain functions in language learning
答案解析：
无学习能力的现象非常普遍。它影响了10％的儿童。无学习能力的男孩的数量是女孩的四倍。
大约从1970年以来，新的研究已经帮助脑科学家更好地探讨了这一问题。科学家现在了解到：有很多不同种类的无学习能力，它们由许多不同的原因引起。可以肯定的是：所有的无学习能力都是由大脑组合在一起的不同方式导致的。
你不可能看一眼某个儿童就说他或她有无无学习能力症，这种疾病没有外在表现。因此，一些研究人员开始研究大脑本身，以便了解哪个部位出了什么问题。
在一项研究中，研究人员检查了一个死于意外事故的无学习能力者的大脑。他们发现了两件不寻常的事情。一件是与大脑左半部的细胞有关的，这些细胞控制语言，这些细胞在正常情况下是白色的。然而，这个无学习能力者的细胞却是灰色的。研究人员还发现，许多神经细胞并没有按照它们应该的方式排成一条直线，而是交织在一起。
这项研究是在诺尔曼·盖茨维德的指导下进行的，他是一个早期研究无学习能力的专家。盖茨维德医生指出，无学习能力主要是由于大脑左半部出现问题造成的。他认为，大脑的这半部分没有正常发育。他说，神经细胞没有按照它们应该的方式连接起来。所以，大脑就像一个线路交叉在一起的电子设备。
其他研究人员没有对脑部组织进行研究。相反，他们检测了脑部的电子活动，并绘制了一幅电子信号图。
弗兰克·达菲在波士顿的儿童医院医学中心用这种技术进行了试验。他发现，正常儿童与那些无学习能力的儿童的脑部活动有很大差异。这些差异遍布大脑。达菲医生说，他的研究证实：无学习能力与大脑许多部位的损伤有关，而不只是与大脑的左半部有关。
1. 【正确答案】D
【解析过程】科学家们发现，没有学习能力的人的大脑细胞和一个正常人的大脑细胞的不同在于 。
线索1：文章的第3段提到“These cells normally are white. In the learning-disabled person，however，these cells were gray.”
线索2：文章的第3段提到“The researchers also found that many of the nerve cells were not in a line the way they should
have been. The nerve cells were mixed together.”
通过线索1和线索2的理解，我们可以判断正确答案应该是选项D.
2. 【正确答案】A
【考点类型】细节判断
【解析过程】下面哪句话是文章没有提到的？
线索1：文章的第7段提到“that reading disabilities involve damage to a wide area of the brain，not just the left side.”表明B在原文中明确提到。
线索2：文章的第3段提到“... nerve cells were mixed together.”表明选项C在文章中出现。
线索3：文章的第5段提到“Doctor Geschwind proposed that learning disabilities resulted mainly from problems in the left
side of the brain.”表明选项D在原文中明确提到。
只有选项A在原文中没有提到。
3. 【正确答案】C
【考点类型】细节排除
【解析过程】下面哪句是不正确的？
线索：文章的第1段提到“They affect perhaps 10 percent of all children.”很清楚是占据了所有孩子的10%，所以选项C是错误答案。A选项在原文的第2段“...and that they are caused by many different things.”明确提到。B选项在原文第3段“There is no outward sign of the disorder.”明确提到。D选项在原文第4段“They found two unusual things...”明确提到。
4. 【正确答案】B
【考点类型】细节判断
【解析过程】达菲医生认为： 。
线索：文章的最后一段提到“Doctor Duffy said his research is evidence that reading disabilities involve damage to a wide area
of the brain，not just the left side.”表明选项B是正确答案。选项C在文章中第4段提到了，但不是达菲说的。
5. 【正确答案】A
【考点类型】细节判断
【解析过程】根据文章，我们可以得出结论：进一步的研究将应该 。
这篇短文所涉及的内容主要是关于无学习能力的人的大脑的发展和组织结构，所以选项A是正确答案。
