题目

阅读理解  A relationship between the amount of adult speech children are exposed to and the concentration of myelin, a substance in the brain, has been found, researchers say.   "I think the take-home message is, absolutely talking to your kids. It's literally shaping the structure of the brain, " says the lead author, Prof. John P. Spencer of the University of East Anglia.  The team find, for the 30-month-olds, larger amounts of adult speech are associated with higher quantities of myelin in language-related pathways in the brain; however, for the 6-month-olds, it goes the opposite way.   While the latter（后者）is unexpected, Spencer points out one possible factor: the brain's stage of development. "When babies are six months old, they experience massive growth of new nerve cells, " he says. "So the input comes in and may help extend the period of brain growth. " "While at 30 months, the brain starts to cut back some of the cell growth, and form specific connections. That's where myelin comes in. So now the input starts to help structure the myelin, " he adds.  The researchers conclude adult speech is significant for both age groups and that the more adult speech children go through, the more sensitive they will be to language. The next step for them is to figure out whether the 6-month-old babies showing that negative connection will surely turn into 30-month-old kids who show positive relationship.   Dr. Saloni Krishnan, Reader in cognitive neuroscience（认知神经科学）at Royal Holloway, University of London, who is not involved in the work, however, notes individual differences in language ability are linked to genetics. "Children who are exposed to more language at home and have higher myelination will also have inherited genes（经遗传获得的基因）from parents who are more excellent in languages, " she said. "No final conclusion could be made before this potential genetic effect are tested. And yet there being currently no standard around the amount of input children should receive, caregivers should not necessarily feel pressure to talk more to their children. " （1） Which can replace the underlined words "take-home message" in paragraph 2? A . Process. B . Reason. C . Point. D . Consequence. （2） What surprises the team?   A . The finding for the 30-month-olds. B . The finding for the 6-month-olds. C . How the input help nerve cells grow. D . How the input help structure the myelin. （3） What does the researchers think of adult speech?   A . It is positively related to myelin. B . It cuts back some of the cell growth. C . Its effect varies with the size of brains. D . It is helpful for both groups' language ability. （4） What might Dr. Saloni Krishnan approve of?   A . The team should do more research. B . Inherited genes decide language ability. C . Parents must talk more to their kids. D . The concentration of myelin makes no sense. 答案： C B D A

查看本题答案和解析