We all know that regular exercise is good for us．In recent years we've been told to aim to walk 10，000 steps a day to remain healthy，although other advice to do three 10-minute walks a day is thought to be even more effective．But the latest piece of research might put a spring in your step if you're someone who walks at a fast pace．That's because，according to scientists，the speed at which people walk in their 40s is a sign of how much their brains，as well as their bodies，are ageing．
   The BBC's Philippa Roxby writes that tests on 1，000 people from New Zealand born in the 1970s found that slower walkers tended to show signs of "accelerated ageing"．Their lungs，teeth and immune systems were in worse shape than those who walked faster．And to add insult to injury，the study found not only did slower walkers' bodies age more quickly，their faces looked older and they had smaller brains．Professor Terrie，lead author of the study，told the BBC： "It found that a slow walk is a problem sign decades before old age．"
   This might be seen as a wake-up call for people with a slower pace who might feel it's time to work out and get fitter．But it might be too late；researchers say they were able to predict the walking speed of 45-year-olds using the results of intelligence，language and motor skills tests from when they were aged three．They also suggest that even in early life，there are signs showing which people will go on to have a healthier life．
   So，what's the point of knowing that a slower walking pace might mean a smaller brain？Well，researchers say measuring walking speed at a younger age，and understanding what this might mean，could be a way of testing treatments to slow human ageing．This might help us make lifestyle changes while we're still young and healthy．Any steps we can take to prolong a good mental and physical state is a no brainer!

（1）What is the text mainly about？

B

B

A．Walking and health．
B．Slow walking and ageing．
C．The way of slowing ageing．
D．The standard walking pace．
（2）What does the latest research show？

D

D

A．Walking 10，000 steps a day helps keep fit．
B．A slower walker is healthier than a faster walker．
C．Slower walkers are easy to have slower brains．
D．Ageing signs of slow walkers arise earlier than fast walkers．
（3）What does the underlined words "wake-up call" refer to in paragraph 3？

C

C

A．Challenge．
B．Potential．
C．Reminder．
D．Solution．
（4）What can we infer from the last paragraph？

A

A

A．Testing walking speed before old age makes sense．
B．It's important to keep fit both physically and mentally．
C．Walking pace is connected with health and ageing．
D．Walking speed at a young age determines one's longevity．