题目内容：

    Your brain isn't necessarily the same age as the rest of you． Now， it may be possible to predict how quickly a person's brain will age throughout life based on tests taken when he or she is three years old．

A person's biological age may be a better indicator of their health than their real age． Brain age can be measured using brain scans and machine﹣learning to determine if a person's brain looks older or younger than the average healthy brain for people of the same age．

To find out if brain age might reveal anything about a person's health in midlife， Max Elliott at Duke University in North Carolina and his colleagues assessed the brains of 869 adults in New Zealand who have undergone regular medical and cognitive （认知的） testing since they were 3 years old．

When the volunteers， all aged between 43 and 46， underwent MRI brain scans， the team found that their brain ages ranged from 23 to 71． Those with older brain ages performed worse on tests of cognition， memory and IQ． The researchers also found that some people have a very advanced brain age but their bodies seem to be ageing slowly， and vice versa （反之亦然）． However， the team found that those who had the highest scores on cognitive tests when they were 3 years old went on to have the youngest﹣looking brains．

This suggests we might be able to tell who is at risk of accelerated brain ageing early in life． Researchers hope that predicting brain ageing earlier in life could allow treatments for conditions like dementia （痴呆） to be started sooner． This means treatments might have a better chance of working．

We don't yet have a way to treat brain ageing， but given the known benefits to the brain of healthy eating and exercise， these aren't a bad place to start．

1.What helps predict the speed of one's brain ageing？

A.One's health condition．

B.A test result at the age of 3．

C.The actual age of one's brain．

D.A machine for medical check．

2.What is the purpose of Elliott's research？

A.To find out why people look older or younger．

B.To measure people's brain age at different stages．

C.To discover whether brain age can be measured by machines．

D.To explore the relationship between brain age and future health．

3.What is Paragraph 4 mainly about？

A.The influence of cognitive tests．

B.The procedure of Elliott's study．

C.The information about volunteers．

D.The findings of the brain research．

4.What do the findings of the research imply？

A.We should test our brain age earliest possible．

B.People suffering dementia can go on working．

C.Brain ageing could be predicted at an early age．

D.Healthy eating and exercise can cure brain ageing．