单项选择题
A．he will use of only about 20 % of the brain's capacity B．the other 80% of his brain will grow in due time C．he had rather narrow forehead a few hundred years ago D．he will have to use his brain more and more as time goes on
A．is always B．hopes for a change C．never stops changing D．will live a different life
A．man has been growing taller over the past 500 years B．man has got stronger eyes than he ever had C．man's hair is getting thinner and thinner D．man's limbs are getting weaker because he tends to make less use of them