笔试选择题（71-80）

一、选择题:((1)-(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)A virtual memory system has five virtual pages numbered zero through four and  three page frames. All the page frames are initially empty. How many page faults are generated with the following access sequence using a FIFO replacement policy?  _____.
(2 Points)
0 1 2 3 0 1 5 0 1 2 3 4 
A) 8 B) 9 C) 10 D) 11

(72)Which element is NOT part of a microkernel? _____.(2 Points)
A) basic I/O B) a file system 
C) IPC mechanisms D) memory management

(73)Which is local to a thread instead of a process? _____.(2 Points)
A) a stack B) an open file C) a semaphores D) an address space

(74)What is a subselect statement?
A)a select statement that selects a subset of fields in a table
B)a select statement that returns a subset of the data in a table
C)a select statement that appears within another select statement
D)a select statement that returns a subset of the constraints on a field

(75)In developing a hospital database,it is determined that on the average,each patient will have 6 treatments during a hospital stay. The averge length of a stay is three days.The hospital has 1000 beds.There are on the average 800 patientsoccupying bedseachday.The relationship between PATIENT and TREATMENT is l:M.The relationship between PATIENT and BED is 1: 1,conditional. If treatment record occurrences are archived as soon as a patient is discharded from the hospital, how many occurrences of the TREATMENT records will be stored in the TREATMENT database file on the  average? _____.(2 Points)
A) 6,000 B) 4,800 C) 18,000 D)1,600

(76)Which of the following conditions will make a relation that is in first normal form  to be in second normal form? _____.
Ⅰ.every non-key attribute is functionally dependent on the full set of primary key 
attributes.
Ⅱ.no non-key attributes exist in the relation.
Ⅲ.the primary key consists of only one attribute.
A) Ⅰ only B) Ⅰand Ⅱ only C) Ⅰand Ⅲ only D) any of them

(77)The most commonly used locking level in implementing concurrency control is at which  of the following levels? _____.
A) database B) table C) record D)field

(78)Which function is NOT served by building a prototype? _____.
A) It takes the place of the final system.
B) It assists in gathering software requirements
C) It assists in estimating the cost of the project.
D) It is used as the foundation of the larger projects.

(79)Software document is an important part of software and a basis of software development  phase.It also influnces software’s _____.(2 Points)
A) Reusability B) Maintanence 
C) Expansibility D) Portability

(80) Which phase of the software development requires the most development time? _____.
A) the design phase B) the testing phase
C) the maintenance phase D) the development phase