A computer is a machine designed to perform work mathematically and to store and select information that has been fed into it. I

admin2013-10-17  29

问题     A computer is a machine designed to perform work mathematically and to store and select information that has been fed into it. It is run by either mechanical or electronic means. These machines can do a great deal of complicated work in a very short time. A large computer, for example, can add or subtract nine thousand times a second, multiply a thousand times a second, or divide five hundred times a second. Its percentage of error is about one in a billion digits. It has been estimated that human beings making calculations average about one mistake per two hundred digits.
    The heart of an electronic computer lies in its vacuum tubes, or transistors. Its electronic circuits work a thousand times faster than the nerve cells in the human brain. A problem that might take a human being two years to solve can be solved by a computer in one minute, but in order to work properly, a computer must be given instructions—it must be programmed.
    Computers can be designed for many specialized purposes, they can be used to prepare payrolls , guide airplane flights, direct traffic, even to play chess. Computers play an essential role in modern automation in many plants and factories throughout the world.
The passage says that computer plays an essential part in______.

选项 A、traffic control
B、mathematical computations
C、the development of mathematical theory
D、automation processes

答案D

解析 文中最后一段最后一句说:“计算机在世界上许多大小工厂的自动化中充当了关键的角色。”由此可判定选项D正确。
转载请注明原文地址:https://kaotiyun.com/show/RNXO777K
0

最新回复(0)