A、It becomes smaller and works faster. B、It becomes larger and works faster. C、It becomes larger and works slower. D、It becomes

M：When was the first computer built?
W：It was built in 1944.
M：Is it the same as the computers that we use now?
W：No，it was as large as a room and worked very slow.
M：But computers have become smaller，and worked faster now.
W：Yes. Most computers are as small as a TV set. Some can be made smaller than a book.
M：Why is a computer so useful?
W：It can keep much information and work very fast.
M：Then they can do a lot of work for us.
W：You are right. They have greatly changed our lives.