The computer plays an important part in our everyday life. It is one of the great           in the world in the 20th century. It works for us not only at home, in the offices, in big shops, but at schools. Today it is used in many ways. It really brings the world large wealth(财富）and     .
The first computer in the world was           Enid. It was built in America in 1946. It was           and heavy. Since it was born, it has been developing very fast. Until now it has           four periods and changed a lot. There're many kinds of computers. Computers are getting smaller and smaller and computing faster and faster. It becomes more and more          .
The computer can do most of the things for people. It can help us to know about the real           more quickly, to learn what we want to learn and to think for ourselves. As a student in the twenty-first century, you must work hard at it.

A．inventions B．discoveries C．robots D．foundations

A．sadness B．worries C．feelings D．happiness

A．founded B．contacted C．called D．invested

A．loose B．large C．tiny D．light

A．gone out B．gone through C．gone on D．gone away

A．serious B．harmful C．dangerous D．useful

A．world B．space C．universe D．knowledge