16.If you want to stay young,sit down and have a good think.This is the research finding of a team of Japanese doctors,who say that most of our brains are not getting enough exercise and,as a result,we are growing old unnecessarily soon.
Professor Taiju Matsuzawa wanted to find out why quite healthy in northern Japan appeared to be losing their ability to think and reason at a rather early age,and how the speed of getting old could be slowed down.
With a team of researchers at Tokyo National University,he set about measuring brain volumes of a thousand people of different ages with different jobs.Computer technology helped the researchers to get most exact measurements of the volume of the front and side parts of the brain,which have something to do with intellect and feelings,and decide the human character.As we all know,the back part of the brain,which controls task like eating and breathing,does not contract with age.
Contraction of front and side parts-as cells die off-was seen in some people in their thirties,but it was still not found in some sixty and seventy-year-olds.
Matsuzawa concluded from his tests that there is a simple way to prevent the contraction-using the head.
The findings show that contraction of the brain begins sooner in people in the country than in the towns."Those with least possibility,"says Matsuzawa,"are lawyers,followed by university professors and doctors.White collar workers doing the same work day after day in government offices are,however,as possible to have contracting brains as the farm worker,bus driver and shop assistant."
72.The team of doctors wanted to find outC.
A.a(chǎn)t what point people grow mentally old
B.how to make people live longer
C.the size of certain people's brains
D.which people are the most clever
73.Their research findings are based onC.
A.a(chǎn)n examination of farmers in northern Japan
B.tests given on a thousand old people
C.examining the brain volumes of different people
D.using computer technology
74.The doctors'tests show thatD.
A.our brains contract as we grow older
B.one part of the brain does not contract
C.sixty-year-olds have better brains than thirty-year-olds
D.some people's brains have contracted earlier than other people's
75.The most possible conclusion of the passage is thatC.
A.most of us take more exercise
B.it's better to live in the town
C.the brain contracts if it is not used
D.the more one uses his brain,the sooner he becomes old.