đề Read the passage and choose the best option for each numbered blank. most people agree that computers are the most important_______ of the 20th century. the first business computers_____ introduced just about fifty years ago, and now they are being used in a wide_____ of fields, from banking to space travel. _____, until just a few decades ago, computers were large, expensive machines _____ by large corporations and governments. 1. A. invention B. discovery C. finding D. view 2. A. are B. were C. have been D. had been 3. A. lots B. many C. variety D. group 4. A. however B. moreover C. therefore D. still 5. A. had B. was C. belonged D. owned