单选题The evidence of electrical activity and other changes in brain cells after the outside stimulus has been got by observing.A exposed cat brainsB the human brainsC cat brains and the human brainsD exposed cat brains and the human brains

请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."

Which of the following statements is true according to the passage?
查看材料

A．Toxoplasma gondii causes people strange and deadly diseases.
B．With certain infection the infectious disease cannot be cured completely.
C．Human beings infected by toxoplasma gondii will have permanent brain damage.
D．Toxoplasma gondii is harmful to human beings, but it does no harm to mice.

The case history of the twins appears to support the conclusion that__________．

A.individuals with identical brains seldom test at the same level
B.an individual's intelligence is determined only by his environment
C.lack of opportunity blocks the growth of intelligence
D.changes of environment produce changes in the structure of the brain

There are two factors which determine an individual's intelligence. The first is the sort of brain he is born with. Human brains differ considerably, some being more capable than others. But no matter how good a brain he has to begin with, an individual will have a low order of intelligence unless he has opportunities to learn. So the second factor is what happens to the individual—the sort of environment in which he is reared. If an individual is handicapped envionmentally ,it is likely that his brain will fail to develop and he will never attain the level of intelligence of which he is capable.
The importance of environment in determining an individual's intellingence can be demonstrated by the case history of the identical twins, Peter and Mark X. Being identical, the twins had identical brains at birth, and their growth processes were the same. When the twins were three months old , their parents died, and they were placed in separate foster homes. Peter was reated by parents of low intelligence in an isolatedcommunity with poor educational pooprtunities.Mark was reared inthe home of well-to-do parents who had been to college. He was read to as a child , sent to good schools, and given every opportunity to be stimulated intellectually.This enviromental difference continued until the twins were in their late teens, when they were giben tesets to measure their intelligence. Mark's I.Q. was 125, twenty-five points higher than the average and fully forty points higher than his identical brother. Given equal opportunities , the twins , having identical brains,would have tested at roughly the same level.
The beststatement of the main idea of this passage is that _C____.

a.human brains differ considerably
b.the brain a person is born with is improtant in determining his intelligence
c.environment is crucial in determining a person's intelligence
d. persons having identical brains will have roughly the same intelligence

If you want to stay young,sit down and have a good think．This is the research result of professor Faulkner,who says that most of our brains are not getting enough exercise and as a result,we are ageing unnecessarily soon.
Professor Faulkner wanted to find out why healthy farmers in northern Japan appeared to be losing their ability to think and to reason at a relatively early age,and how the process of ageing could be slowed down.
He set about measuring brain volumes of a thousand people of different ages and occupations．
Computer technology enabled him to obtain precise measurements of the volume of the front and side sections of the brain,which relate to intelligence and emotion,and determine the human character．
Contraction of front and side parts--as cells die off--was observed in some subjects in their thirties,but it was still not evident in some sixty-and seventy-year-olds.
Faulkner concluded from his tests that there is a simple way to slow 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 least at risk,says Faulkner,are lawyers,followed by university professors and doctors．White--collar workers doing routine work are,however,as likely to have shrinking brains as the farm worker,bus driver and shop assistant.
Faulkner's findings show that thinking can prevent the brain from shrinking．Blood must circulate properly in the head to supply the fresh oxygen the brain cells need．"The best way to maintain good blood circulation is through using the brain,"he says．"Think hard and engage in conversation．Don't rely on pocket calculators."

Professor Faulkner wanted to find out__．

A.how people's brains shrink
B.the way of making people live longer
C.the size of certain people's brains
D.why certain people aged sooner than others

The WHO says there is currently no evidence of human-to-human ______ of the virus.

A.translation
B.transition
C.transmission
D.transaction

It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."

The experiment found that mice infected with toxoplasma gondii__________.查看材料

A.stayed far away from cat’s urine
B.moved around the area freely and tearlessly
C.because more sensitive to cat's smell
D.were more afraid of cats

There are two factors which determine an individual's intelligence． The first is the sort of brain he is born with． Human brains differ considerably, some being more capable than others． But no matter how good a brain he has to begin with, an individual will have a low order of intelligence unless he has opportunities to learn． So the second factor is what happens to the individual--the sort of environment in which he is brought up． If an individual is handicapped environmentally, it is likely that his brain will fail to develop and he will never attain the level of intelligence of which he is capable．
Theimportanceofenvironmentindetermininganindividual'sintelligencecanbe?
demonstrated by the case history of the identical twins, Peter and Mark． Being identical, the twins had identical brains at birth, and their growth processes were the same． When the twins were three months old, their parents died, and they were placed in separate foster homes． Peter was raised by parents of low intelligence in an isolated community with poor educational opportunities． Mark was reared in the home of well-to-do parents who had been to college． He was read to as a child, sent to good schools, and given every opportunity to be stimulated intellectually． This environmental difference continued until the twins were in their late teens, when they were given tests to measure their intelligence． Mark's LQ． was 125, twenty-five points higher than the average and fully forty points higher than his identical brother． Given equal opportunities, the twins, having identical brains, would have tested at roughly the same level．
?The best statement of the main idea of this passage is that__________．

A.human brains differ considerably
B.the brain a person is born with is important in determining his intelligence
C.environment is crucial in determining a person's intelligence
D.persons having identical brains will have roughly the same intelligence

（ ）makes computers able to do jobs which till now, only human brains can do.

A.Artificial intelligence
B.Big data
C.Cloud computing
D.Internet of things

There are two factors which determine an individual's intelligence. The first is the sort of brain he is born with. Human brains differ considerably, some being more capable than others. But no matter how good a brain he has to begin with, an individual will have a low order of intelligence unless he has opportunities to learn. So the second factor is what happens to the individual—the sort of environment in which he is reared. If an individual is handicapped envionmentally ,it is likely that his brain will fail to develop and he will never attain the level of intelligence of which he is capable.
The importance of environment in determining an individual's intellingence can be demonstrated by the case history of the identical twins, Peter and Mark X. Being identical, the twins had identical brains at birth, and their growth processes were the same. When the twins were three months old , their parents died, and they were placed in separate foster homes. Peter was reated by parents of low intelligence in an isolatedcommunity with poor educational pooprtunities.Mark was reared inthe home of well-to-do parents who had been to college. He was read to as a child , sent to good schools, and given every opportunity to be stimulated intellectually.This enviromental difference continued until the twins were in their late teens, when they were giben tesets to measure their intelligence. Mark's I.Q. was 125, twenty-five points higher than the average and fully forty points higher than his identical brother. Given equal opportunities , the twins , having identical brains,would have tested at roughly the same level.
The case history of the twins appears to support the conclusion that ___C____.

a.individual with identical brains seldom test at same level
b.an individual's intelligence is determined only by his enviroment
c.lack of opportunity blocks the growth of intelligence
d.changes of enviroment produce changes in the structure of the brain

If you want to stay young,sit down and have a good think．This is the research result of professor Faulkner,who says that most of our brains are not getting enough exercise and as a result,we are ageing unnecessarily soon.
Professor Faulkner wanted to find out why healthy farmers in northern Japan appeared to be losing their ability to think and to reason at a relatively early age,and how the process of ageing could be slowed down.
He set about measuring brain volumes of a thousand people of different ages and occupations．
Computer technology enabled him to obtain precise measurements of the volume of the front and side sections of the brain,which relate to intelligence and emotion,and determine the human character．
Contraction of front and side parts--as cells die off--was observed in some subjects in their thirties,but it was still not evident in some sixty-and seventy-year-olds.
Faulkner concluded from his tests that there is a simple way to slow 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 least at risk,says Faulkner,are lawyers,followed by university professors and doctors．White--collar workers doing routine work are,however,as likely to have shrinking brains as the farm worker,bus driver and shop assistant.
Faulkner's findings show that thinking can prevent the brain from shrinking．Blood must circulate properly in the head to supply the fresh oxygen the brain cells need．"The best way to maintain good blood circulation is through using the brain,"he says．"Think hard and engage in conversation．Don't rely on pocket calculators."

The professor's tests show that__.

A.our brains shrink as we grow old
B.the front section of the brain does not shrink
C.seventy-year-olds have better brains than sixty-year-olds
D.brain contraction may vary among people of the same age

It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."

Which of the following statements is true according to the passage 查看材料

A.Toxoplasma gondii causes people strange and deadly diseases.
B.With certain infection the infectious disease cannot be cured completely.
C.Human beings infected by toxoplasma gondii will have permanent brain damage.
D.Toxoplasma gondii is harmful to human beings, but it does no harm to mice.

Human‘s brains are larger in proportion to their bodies than_______．

A.whales
B.a whale
C.that of whales
D.those of whales