Câu 1:
Most people agree that computers are the most important invention of the 20th century. The first business computers were introduced just about fifty years ago, and now they are being used in a wide variety of fields, from banking to space travel. However, until just a few years ago, computers were very large, expensive machines owned by large existed, very few people had ever seen one an even fewer had used one. Then in the 1970s the silicon chip was invented. Because this electronic device could store a large amount of information in a very small space, computer could be much smaller and less expensive then the huge mainframe computers used by corporation. Some computer manufactures believed that people might want to have computers in their homes, offices, and schools, so the personal computers was born