Life in 21st century（世纪） will be different from the life in the 20th century , because many changes will take place in the century, but what will the change be? The population(人口) is growing fast. There will be more and more people in the world and most of them will live longer than before .Computers will be much smaller and useful, and there will be at least(至少) one in every family. And computer studies will be one of the most important subjects in school. People will work fewer hours than they did in 20th century. They will have more free time for sport