What will man be like in the future in 5, 000 or even 50, 000 years from now？ We can only

make a guess, of course, but we【56】be sure that he will be different from what he is【57】. For man is【58】changing all the time.

Let us take an obvious example.【59】, even five hundred years ago, was shorter than he is today. Now, on average, men are about three inches【60】. Five hundred years is【61】relatively short period of time, so we may assume that man will【62】to grow taller.

Again, in the modern world we use our brains【63】. Even so, 【64】still make use of only about 20% of the brain's capacity.【65】time goes on, however, we【66】use our brains more and more, and eventually we shall need larger ones \【67】is likely to bring about a physical change too: the head, in particular the forehead, will grow larger.

Nowadays our eyes are in constant use. In fact, we use them so much that very often they become【68】and we have to wear glasses. But【69】very long period of time it is likely that man's eyes will grow【70】

On the other hand, we tend to make【71】use of our arms and legs. These, as a result, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive because they【72】a great deal in modern life.

【73】what about hair？ This will probably【74】from the body altogether in course of time because it does not serve a【75】purpose any longer. In the future, then, both sexes are likely to be bald.

(56)

A．can

B．can't

C．should

D．shouldn't