2017计算机等级考试四级笔试必备题

计算机等级证书是我们找工作的敲门砖，现在越来越多人重视计算机等级考试。以下是本站小编整理的2017计算机等级考试四级笔试必备题，欢迎学习!

(1) 网络中的计算机之间要做到有条不紊地交换数据就必须遵守网络协议，一个网络协议主要包括三个要素，即____。

A) 语法、原语与数据 B) 语义、数据与软件

C) 层次、接口与原语 D) 语法、语义与时序

(2) 当PCM用于数字化语音系统时，它将声音分为128个量化级，每个量化级采用7位二进制码表示。由 于采样速率为8000样本/秒，因此，数据传输速率应该达到____。

A) 2880bps B) 56Kbps C) 144Kbps D) 1200bps

(3) 具有分时系统文件管理的全部功能，提供网络用户访问文件、目录的`并发控制与安全保密功能的局域网服务器叫做____。

A) 电子邮件服务器 B) WWW服务器

C) 文件服务器 D) FTP服务器

(4) 在网络层实现多个局域网互连的设备是____。

A) 集线器 B) 网桥 C) 路由器 D) 网关

(5) 在WWW系统中，用户可以根据需要自动从一台Web Server搜索到其他任何一台Web Server，它所采用的是____。

A) 超文本(hypertext)技术 B) 超链接(hyperlink)技术

C) 超媒体(hypermedia)技术 D) 超文本标注语言HTML

(6) Give the logical variables X=Y=1, The value of X V Y(logical addition)

is____.

A) 1 B) 2 C) 10 D) 0

(7) The Programming Counter (PC) is normally used to point out____.

A) Programmed execution instruction

B) The address of last execution instruction

C) The address of current execution instruction

D) The address of next execution instruction

Items (58) and (59) are based on the following Pascal code.

FOR i:=1 TO n -1 do

BEGIN

k:=i:

FOR j:=i+1 TO n DO

IF A[j]br> THEN k:=j:

IF k<>i

THEN BEGIN

X:=A[k];

A[k]:=A[i];

A[i]:=x

END

END;

(8) The sorting method described by the code is called____.

A) Insertion sort B) Selection sort C) Radix sort D) Merge sort

(9) Suppose elements in array A are already sorted ascending order of their

values when the code begins to run, then execution time of the code will be____.

A) O(log2n) B) O(n) C) O(nlog2n) D) O(n2)

(10) Assume that N=2M and FIFO is used. If the string p1,p2,…,pN is repeated

three times, then the number of page faults is____.

A) N/2 B) N C) 2N D) 3N

(11) Chang, Tian and An are three users of the system. Chang and An are in

the same group. Tian is a Super User. Which of the following rights is inconsistent

with the given policies?____.

A) Tian has W(write) access to An's Mail files

B) Tian has E(execute) access to An's Mail files

C) Chian has R(read) access to An's text files

D) Tian has E(execute) access to Chang's Binary files

(12) Software Engineering Economy is an effective part of software engineering,

which of the fo llowing content is the research comtent of software engineering

economy?____.

Ⅰmation of software development cost

Ⅱ & Cost analysis of software development

Ⅲstment of software development progress

A) Ⅲ only B) Ⅱ and Ⅲ C) Ⅰ and Ⅱ D) all

(13) Prototype method is one of the software engineering methods frequently

used, which of the following item is the necessary condition for implementing

prototype method?____.

Ⅰ acquire the user requirement quickly

Ⅱ the tools for building software fast

Ⅲ a certain accumulation of prototype systems

A) Ⅰ only B) Ⅰand Ⅱ C) Ⅱ and Ⅲ D) all

(14) ORACLE RDBMS is a distributed DBMS. Which of the following techniques

adapted ensure atomicity of distributed transaction?____.

A) remote procedure call (RPC) B) Two _phases commit (2PC)

C) Snapshots D) triggers

(15) In order to get names of schoolboys(SEX='M')whose age=22, from a relation____.

S(SNO,SNAME,SEX,AGE),which of the following expressions is (are) correct?

Ⅰ.πsname(σsex='M'^age=22(S))

Ⅱ.σsex='M'^age=22(πsname(S))

A) Ⅰ only B) Ⅱ only C) Ⅰand Ⅱ D) neither

(16) In order to improve the performance of a network server, you need to select

bus or local bus. The appropriate local bus is____.

A) VESA B) PCI C) EISA D) ISA

(17) In terms of n's taxonomy, the systolic array falls into____.

A) SISD B) MIMD C) SIMD D) MISD

(18) In the WAN, when a point-to-point subnet is used, an important design

issue is the roucer interconnection____.

A) topology B) computer C) service D) lines

(19) In the Ethernet LAN, an algorithm was chosen to dynarnically adapt to

the number of stations trying to send. It is called____.

A) backward learning B) binary exponential backoff

C) spanning tree D) CRC

(20) The typical firewall consists of two packet filters and a (an)____.

A) router B) bridge C) application D) server