笔试选择题（71-80）

一、选择题。(共90题,分为1分题和2分题,满分120分。除标注2分题外,其它均为1分题。）

(71) In order to append a standard output to an existing file, which of the following operators is used in the UNIX system? ____． 
A) |  B) &  C) >  D) >>  

(72) Consider the following figure, where the shaded parts represent already assigned blocks of memory,  and the unshaded parts represent free blocks. (2分)  If there is a request for 40KB of memory and the best-fit algorithm is used, then the beginning address of memory that is allocated in response to the request is ____.  　  　
A) 100KB B) 190KB C) 330KB D) 410KB

(73)  On a certain disk, there are 200 tracks, numbered 0-199, the current position of the disk head is track 53. If the shortest-seek-time-first scheduling algorithm is used when the tracks  
98, 183, 37, 122, 14, 124, 65, 67  
are requested, then the head-moving sequence that results will be (2分)  
A) 65, 67, 37, 14, 98, 122, 124, 183  
B) 65, 67, 37, 98, 122, 124, 183, 14  
C) 65, 67, 98, 122, 124, 183, 37, 14  
D) 98, 183, 37, 122, 14, 124, 65, 67  

(74) Whant operation on relations R and S produces the relation shown below?____.   
{tuple│tuple∈R۸tuple∈\ S}  
A) Union B) Difference C) Intersection D) Division  

(75) When embedding SQL in a C language program, the prefix that should be added   to all SQL statements in order to distinguish SQL statements from the host language statements is____.   
A) ： B) EXEC C) EXEC SQL D) SQL  

(76) In the ORACLE system,sets of SQL statements and control flow statements that have been named,compiled,and stored tn the database are referred to as stored____.   
A) batches B) procedures C) triggers D) transactions  

(77) Which of the following statements about object oriented databases is NOT correct? ____. (2分)  
A) Each object has a unique object identity in the system.  
B) Encapsulation and inheritance are two important features of object oriented databases.  
C) A subclass can inherit the attributes and methods of all its superclasses.  
D) A superclass includes the attributes and methods of all its subclasses.  

(78) In the design phase of software engineering, decomposition of the program into modules should follow the principles of ____.  
A) low cohesion with low corpling B) low cohesion with high coupling  
C) high cohesion with low coupling 　D) high cohesion with high coupling  

(79) Specifications for software should contain&nbs  p;several components, e.g., specifications of   
information flow,  
user interface,  
functional requirements, and  
design constraints.  
Two other important components are specifications of the____.  (2分)  
A) methods of testing and ways to obtain quality assurance  
B) criteria for testing and ways to obtain quality assurance  
C) methods of testing and criteria for function assurane  
D) criteria for testing and methods of function assurance 

(80) Which of the following statements about testing software with data is (are) true?____.   
I. The primary purpose of such testing is to find errors.  
II. Such testing can demonstrate the existence of errors but cannot  
demonstrate the absence of errors.  
A) Neither B) Ⅰ only C) Ⅱ only D) Ⅰ and Ⅱ