There are many people in the world now. There     22     (be) a lot more people in the next century. The earth will be very     23     (crowd), so there will be a little room     24     each person. Maybe there will be only standing room on the earth 600     25     (year) later. That will be a very serious problem.     26     man is thinking of a way to solve the problem.

The moon is the satellite of the earth. Maybe man will go     27     (live) on the moon one day. But there is no air, no plants     28     no life there. So scientists     29     (do) experiments now in many ways. They have to solve many problems     30     man can live on the moon. I am sure our dreams     31     (come) true in the next century.

What will people look like in the future? Someone made a ________.

In the future, people will have larger heads and bigger eyes. The larger heads will be able to store ________ brains. People will become smarter. ________ will people have bigger eyes? That’s because people may go and live on other ________. They may be farther ________ the sun than the earth is. Then people will need bigger eyes to see ________ in the darker environment. ________ UV radiation (紫外线辐射) is stronger on other planets than that on the earth, people’s skin (皮肤) won’t be so ________ as before. What’s more, people will not need to open their mouths to ________. They will communicate by chips in their heads.

What? You don’t want a face like this? Don’t ________. People will look like this in at least 20,000 years.