2016年计算机四级考试选择题

为了帮助大家更好备考2016年上半年的计算机四级考试，小编为大家准备了以下四级考试选择题，希望对大家有所帮助!

1)以下关于网络协议三个要素之一的语法的描述，哪一个是正确的?

A)语法解释比特流的.每一部分的意义

B)语法规定用户数据与控制信息的结构与格式

C)语法对事件实现的顺序作了详细地说明

D)语法对协议实现方法作出明确的规定

2)如果物理层采用了曼彻斯特编码，那么信号传输速率为10Mbps时，发送时钟信号频率应该为

A)5MHz B)10MHz

C)15MHz D)20MHz

3)符合IEEE802.3标准的Ethernet网物理地址采用连续编码方法，它使用的地址长度为

A)8bit B)16bit

C)48bit D)64bit

4)网络环境中实现分布式进程通信必须解决哪3个主要的问题?

Ⅰ. 进程命名与寻址方法 Ⅱ. 多重协议的识别

Ⅲ. 协议转换 Ⅳ. 进程间相互作用的模式

A)Ⅰ、Ⅱ和Ⅲ B)Ⅰ、Ⅱ和Ⅳ

C)Ⅱ、Ⅲ和Ⅳ D)Ⅰ、Ⅲ和Ⅳ (55)10Gbps Ethernet与10Mbps、100Mbps和1Gbps Ethernet采用了完全相同的

Ⅰ. 帧格式 Ⅱ. 逻辑链路控制子层协议

Ⅲ. 物理层标准 Ⅳ. 数据编码方法

A)Ⅰ和Ⅱ B)Ⅰ、Ⅱ和Ⅲ

C)Ⅱ和Ⅳ D)Ⅱ、Ⅲ和Ⅳ

6)What is the decimal value of the binary value 10010?

A)16 B)17 C)18 D)19

7)In a computer, which of the following is the longest period?

A)Beat period B)Machine period C)Instruction period D)CPU period

8)Which of the following is not an AVL tree?

9)Traversing a binary tree in preorder is equivalent to

A)Traversing the forest corresponding to the binary tree in root-first order.

B)Traversing the forest corresponding to the binary tree in root-last order.

C)Traversing the forest corresponding to the binary tree in breadth-first order.

D)None of the above.

10)Which of the following methods is used to increase the number of processes sharing the CPU?

A)Interrupt B)Scheduler

C)Swapping D)Working Set

11)Which of the following statements describe(s) the properties of a purely segmented memory system?

Ⅰ divides memory into units of equal size

Ⅱ permits implementation of virtual memory

Ⅲ suffers from internal fragmentation

A)Ⅰ only B)Ⅱ only

C)Ⅲ only D)Ⅰand Ⅲ

12)As an important phase in software development, software design is the continuation of software requirement analysis phase.

Ⅰware structure Ⅱware procedure

Ⅲware module Ⅳware document

which of the following should be included in software design phase?

A)Ⅰand Ⅱ B)Ⅱand Ⅲ

C)Ⅰ,Ⅱ and Ⅲ D)All

13)White box testing of software testing is a test for software structure. Which of the following item should not be included in the content of white box?

A)boundary value analysis B)statement testing

C)branch testing D)path testing

14)Consider a relation R ( A，B，C，D ) with the following dependencies：

AB ? C, CD ? E, DE ? B.

A candidate key of this relation is

A)AB B)ABC C)ABD D)ABE

15)Let R and S be the following relations：

A)3 B)4 C)5 D)6

16)The Pentium includes hardware for both segmentation and paging. Both mechanisms can be disabled, allowing the user to choose from four distinct views of memory. Now the most frequently used view(such as Unix System V) is

A)Unsegmented unpaged memory B)Unsegmented paged memory

C)Segmented unpaged memory D)Segmented paged memory

17)ASCII is a 7-bit code used to represent numeric, alphabetic, and special printable characters. It also includes codes for control characters, which are

A)printable or displayable B)not printable or displayable

C)not printable but displayable D)printable but not displayable

18)In most wide area networks, the communication

;subnet consists of two distinct components：transmission lines and

A)networts B)switching elements

C)computers D)data terminal equipment

19)To accommodate the longest path allowed by 802.3,the slot time has been set to 512 bit times,or

A)0.512μs B)5.12μs

C)51.2μs D)512μs

20)TCP(Transmission Control Protocol) was specifically designed to provide a reliable end-to-end byte stream over a(n)

A)IP address B)reliable network

C)socket D)unreliable internetwork