云南开放大学计算机专业英语第二章网上作业

一、阅读理解(共5题,共100分)
A general purpose computer has fourmain components: the arithmetic logic unit (ALU), the control unit, the memory,and the input and output devices （collectively termedI/O). These parts are interconnected by buses, often made of groups of wires.
Inside each of these parts aretrillions of small electrical circuits which can be turned off or on by meansof an electronic switch. Each circuit represents a bit (binary digit) ofinformation so that when the circuit is on it represents a “1”, and when off itrepresents a “0” (in positive logic representation). The Circuits are arrangedin logic gates so that one or more of the circuits may control the state of oneor more of the other circuits.
The control unit, ALU, registers,and basic I/O (and often other hardware closely linked with these) arecollectively known as a central processing unit (CPU). Early CPUs were composedof many separate components but since the mid-1970s CUPs have typically beenconstructed on a single integrated circuit called a microprocessor.
The control unit (often called acontrol system or central controller) manages the computer’s variouscomponents; it reads and interprets, (decodes) the program instructions,transforming them into a series of control signals which activate other partsof the computer. Control systems in advanced computers may change the order ofsome instructions so as to improve performance.
1.（20分）
A generalpurpose computer has four main components: the arithmetic logic unit, thecontrol unit,         , and theinput and output devices.
A. mouse.
B. the  memory.
C. display.
D. disc.
正确答案: B
2.（20分）
If thecircuit is on, it represents a          (in positive logic representation)
A. “1”
B. ”0”
C. ”on”
D. ”off”
正确答案: A
3.（20分）
The central processingunit is composed of       components.
A. three
B. six.
C. four.
D. five
正确答案: C
4.（20分）
the controlunit can not
A. read theprogram instructions
B. transformthe program instructions into a series of control signals
C. print docu-ments
D. interpret the programinstructions
正确答案: C
5.（20分）
The control unit iscalled
A. a centralsystem
B. a CPU
C. a control circuit
D. a control system
正确答案: D