第8题: [单项选择]This passage mainly discusses ______. A. the history of computer B. the different functions of computer C. the computer in the 21st century D. the scientific breakthroughs in the 21st century 参考答案:C 答案解析:本题为主旨归纳题。作者在第一段就开门见山地指出21世纪科学领域里的许多突破将会导致机械将在许多领域内替代人脑完成工作,电脑将在许多领域内有所作为。