单选题By calling it “tap-dancing to work”, Warren Buffett thinks the author’s job is _____A a great challenge to brain power.B significant in the development of technology.C enjoyable in spite of any possible hardships.D a window through which people are sho

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第二篇

Exercise and Brain

Just as exercise strengthens the heart and lungs,bones and muscles,it may also power up the brain.A succession of scientific studies of animals implies that physical activity has a positive effect on mental functioning.
"It's clear that the brain benefits from exercise,"says brain scientist William Greenough of the University of Illinois at Urbana-Champaign.His studies with rats have demonstrated two primary effects of activity:Vigorous physical exercise provides the brain with more fuel,and skill-based ex-ercise increases the formation of connections in the brain, which, according to the proposals of some scientists,may make the brain better able to process information.
In one experiment,laboratory rats were separated into three groups.One group was exercised by running inside an automatic wheel,a second group improved their skills in a complicated obstacle course,and a third group was inactive.
"The animals that learned to go through the obstacle course exhibited a greater number of brain connections than the animals in the exercised or inactive groups,"Greenough said."In contrast, the animals that exercised inside the automatic wheel possessed a greater density of blood vessels in the brain than did either of the other two groups of animals."
Learning a new dance step may boost the brain in the same way that learning a language can, he says.And if the dance is a good physical exercise as well,the benefits multiply.Young brains may be especially able to boost brain power through exercise,suggested another of Greenough's experiments that showed the most significant changes in the brain occurred among rats that had been exercised when very young.And while animals aren't people,he says it is logical to make the inference that an effect found in rats may also apply to humans.
Human studies have focused primarily on older adults and suggest that regular exercise can improve the speed with which the brain processes information.Measurements made by Arthur Kramer at the University of Illinois demonstrated that inactive adults,aged 63 to 82,could hit buttons faster in response to a tone after they went through a 10-week water exercise course.A corresponding control group that didn't exercise showed no improvement.

Which statement is correct according to the passage?
A:The effect of exercises found in rats can not apply to people.
B:Changes in the brain occurred among young rats are more significant than those among adult rats.
C:Regular exercise can only improve the speed with which the older adults' brain processes information.
D:The author encourages people do more skill-based exercise instead of vigorous physical exercise.

The author says that he is a naturalist rather than a scientist probably because he thinks he__________.

A.just reads about other people's observations and discoveries
B.comes up with solution in most natural ways
C.has a great deal of trouble doing mental arithmetic
D.lacks some of the qualities required of scientist

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第三篇

Smart Exercise

Doctors are starting to find more and more information that suggests a connection
between exercise and brain development.Judy Cameron,a scientist at Oregon Health and
Science University,studies brain development.According to her research,it seems that
exercise can make blood vessels,including those in the brain,stronger and more fully
developed.Dr. Cameron claims this allows people who exercise to concentrate better. As
she says:"While we already know that exercise is good for the heart,exercise can literally
cause physical changes in the brain."
The effects of exercise on brain development can even be seen in babies.Babies who
do activities that require a lot of movement and physical activity show greater brain
development than babies who are less physically active.With babies,even a{ittle
movement can show big results. Margaret Barnes , a pediatrician（儿科医师）,believes in
the importance of exercise.She thinks that many learning disabilities that children have in
elementary school or high school can be traced back to a lack of movement as babies.
"Babies need movement that stimulates their five senses.They need to establish a
connection between motion and memory.In this way,as they get older,children will begin
to associate physical activity with higher learning,"says Margaret.
Older people can beef up their brains as well.Cornell University studied a group of
seniors ranging in age from seventy to seventy-nine. Their study showed a short-term
memory increase of up to 40 percent after exercising just three hours a week.The exercise
does not have to be very difficult,but it does have to increase the heart rate.Also,just like
the motion for infants,exercise for older people should involve some complexity.Learning
some new skills or motions helps to open up memory paths in the brain that may not have
been used for a long time.
For most people,any type of physical activity that increases the heart rate is helpful.
The main goal is to increase the brain's flow of blood.And your brain can benefit from as
little as two to three hours of exercise a week.

Research by Dr.Cameron seems to suggest that exercise can
A: generate new blood vessels.
B:change the way a person thinks.
C: promote brain development.
D: divert one's attention.

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Albert Einstein's Brain

1.It doesn't take an Einstein to recognize that Albert Einstein's brain was very different from yours and mine.The gray matter housed inside that shaggy head managed to revolutionize our concepts of time,space,motion一the very foundations of physical reality一not just once but several times during his astonishing career. Yet while there clearly had to be something remarkable about Einstein's brain,the pathologist who removed it from the great physicist's skull after his death reported that the organ was,to all appearances,well within the normal range一no bigger or heavier than anyone else's.
2.But a new analysis of Einstein's brain by Canadian scientists,reported in the current Lancet, reveals that it has some distinctive physical characteristics after all. A portion of the brain that governs mathematical ability and spatial reasoning一two key ingredients to the sort of thinking Einstein did best一was significantly larger than average and may also have had more interconnections among its cells,which could have allowed them to work together more effectively.
3.In 1996,Harvey gave much of his data and a significant fraction of the tissue itself to Dr. Sandra Witelson,a neuroscientist who maintains a"brain bank"at McMaster for comparative studies of brain structure and function.These normal,undiseased brains,willed to science by people whose intelligence had been carefully measured before death, gave Witelson a solid set of benchmarks against which to measure the seat of Einstein's brilliant thoughts.Not only was Einstein's inferior parietal region unusually bulky the scientists found,but a feature called the Sylvian fissure was much smaller than average.Without this groove that normally slices through the tissue,the brain cells were packed close together,permitting more interconnections一which in principle can permit more cross-referencing of information and idea, leading to great leaps of insight.
4.That's the idea,anyway.But while it's quite plausible according to current neurological theory,that doesn't necessarily,make it true.We know Einstein was a genius,and we now know that his brain was physically different from the average.But none of this proves a cause-and-effect relationship."What you really need,"says McLean's Benes,"is to look at the brains of a number of mathematical geniuses to see if the same abnormalities are present."
5.Even if they are,it's possible that the bulked一up brains are a result of strenuous mental exercise,not an inherent feature that makes genius possible.Bottom line:we still don't know whether Einstein was born with an extraordinary mind or whether he earned it,one brilliant idea at a time.

The structure of brain________.
A:that doesn't necessarily make it true
B:the cells of mathematics
C:was born with an extraordinary mind or he earned it
D:allow the cells work together more effectively
E:is the same as the averages in size and weight