What will man be like in the future — in 5,000 or even 50,000 years from now? We can only make _____, of course, but we can be sure that he will be different from what he is today, for man is slowly _____ all the time.

Let us take an obvious _____. Man, even five hundred years ago, was shorter than he is today. Now, on average, man is about three inches taller. Five hundred years is a relatively short period of time, so we may _____ that man will continue to grow taller. Again, in the modern world we use our brains a great deal. Even so, we still make use of only about 20% of the brain’s capacity (能力). As time goes on, _____, we shall have to use our brains more and more, and _____ we shall need larger ones! This is likely to _____ a physical change to the head, and in particular the forehead, which will grow larger.

Nowadays our eyes are in _____ use. In fact, we use them so much that very often they become _____ and we have to wear a pair of glasses. But over a very long period of time it is likely that man’s eyes will grow stronger.

On the other hand, we have a (n) ______ to make less use of our arms and legs. They, ______, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive ______ they are used a great deal in modern life.

Another we are ______ about is our hair. This will ______ from the body altogether in the course of time because it does not ______ a useful purpose any longer. In the future, then, both sexes are likely to be bald (秃顶的).

Perhaps all this gives the ______ that future man will not be a very ______ creature to look at! This may well he true. All the same, ______ all these changes, future man will still have a lot in ______ with us. He will still be a human being, with thoughts and ______ similar to our own.