捷成计算机等级考试四级模拟试题4

1、捷成计算机等级考试四级模拟试题（第四套）1) P(n) is the predicate 'if 4 divide n then 2 divides n'. A) 10 B) F C) T D) None of the above 2) What is the definition of a Path A) A sequence and the edges formed by each successive pair of vertices. B) A walk with distinct vertices. C) A walk with distinct edges. D)

2、None of the above. 3) Which UNIX command creates a symbolic link named myfile in the current directory to the file/etc/hosts A) ln -s /etc/hosts myfile B) ln -s myfile /etc/hosts C) link -s /etc/hosts myfile D) link -s myfile /etc/hosts 4) Which MS-DOS command is correct A) DEL /S *.bat B) DEL *.exe

3、/SP C) DEL *.obj>NUL: D) DEL *.com *.sys5) 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 0 1 2 3 0 1 4

4、0 1 2 3 4 A) 8 B) 9 C) 10 D) 11 6) Which element is NOT part of a microkernel? A) basic I/O B) a file system C) IPC mechanisms D) memory management 7) Which is local to a thread instead of a process? A) a stack B) an open file C) a semaphores D) an address space8) What is a subselect statement? A) a

5、 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 9) In developing a hospital dat

6、abase, it is determined that on the average, each patient will have 6 treatments during a hospital stay. The average length of a stay is three days. The hospital has 1000 beds. There are on the 800 patients occupying beds each day. The relationship between PATIENT and TREATMENT is 1:M. The relations

7、hip 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? A) 6,000 B) 4,800 C) 18,000 D) 1,60010) Whic

8、h of the following conditions will make a relation that is in first normal from to be in second normal form? . every non-key attribute is functionally dependent on the full set of primary key attributes. . no non-key attributes exist in the relation. . the primary key consists of only one attribute.

9、 A) only B) and only C) and only D) any of them 11) 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 12) Which function is NOT served by building a prototype? A) It takes the place of the final syste

10、m. B) It assists in gathering software requirements. C) It assists in estimating the cost of the project. D) It is used as the fundation of the larger projects.13) Software document is an important part of software and a basis of software development phase. It also influnces software's? A) Reusa

11、bility B) Maintanence C) Expansibility D) Portability 14) 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 15) Black-box and white-box testing method are often used in software testi

12、ng phase, in which, the white-box is mainly used to test software's? A) reasonableness of structure B) correctness of a program C) external function of a program D) internal logic of a program 16) How does Booth's Algorithm improve binary multiplication? A) It prevents overflow. B) It preven

13、ts underflow. C) It preserves the sign of the multiplication operation. D) It enhances the speed of the operation significantly.17) A cache has 64 blocks; each block is 16 bytes. Which block does byte 1200 map to? A) 25 B) 60 C) 75 D) 10018) Which is NOT a characteristic of an RISC processor? A) a h

14、igh clock speed B) a highly optimized pipeline C) a few general-purpose registers D) a limited amount of small instructions19) You are performing two sums: the first is a sum of two scalar variables and the second is a matrix sum of a pair of two-dimensional arrays-size 1000 by 1000. What speedup is

15、 achieved when the calculations are performed on size 1000 processors? A) 50 B) 100 C) 999 D) none of above20) According to Shannon's equation, what is the channel capacity of an analog voice-grade phone line with a bandwidth of 3100 Hz and a signed-to-noise ratio or 30dB? A) 9.1 Kbps B) 9.3 Kbp

16、s C) 30.9 Kbps D) 30.17 Kbps 21) The X.25 standard specifies three layers of functionality. Which layers of the OSI model correspond to the X.25 layers? A) the Physical, Network, and Session Layers B) the Physical, Data Link, and Network Layers C) the Physical, Data Link, and Transport Layers D) the

17、 Physical, Session, and Presentation Layers 22) Which routing algorithm is described below? It is a mechanism in which the sending station determines the route the frame will follow and includes the routing information with the frame;bridges read the routing information to determine if they should f

18、orward the frame. A) Fixed Routing B) Spanning Tree C) Source Routing D) Frame Forwarding23) Which OSI layer does a bridge operate at? A) the Physical Layer B) the Network Layer C) the Transport Layer D) the Data Link Layer 24) There are several periods in a computer, the shortest period is? A) Inst

19、ruction period B) Machine period C) Beat period D) CPU period 25) What is the contrapositive of the following implication? "If it is raining, then I get wet." A) If I get wet, then it is raining. B) If I am wet, then it is raining. C) If it is not raining, I do not get wet. D) If I do not

20、get wet, then it is not raining. 26) Which property does R posses? Let A=1,2,3,4 and let R=<1,2>,<2,2>,<3,4>,<4,1>. A) Symmetry B) Reflexivity C) Asymmetry D) Antisymmetry27) When walking a tree, which traversal method yields a prefix, or Polish,form? A) Inorder B) Preorder C

21、) Postorder D) Reorder 28) In the following statement about graph operations, which one is NOT correct? A) Spanning tree of a graph may not be unique. B) Minimum spanning tree of a graph may not be unique. C) Finding critical path is an operation on directed graph. D) Finding critical path is an ope

22、ration on undirected graph. 29) What storage scheme does MS-DOS use for storing files on a disk? A) I-nodes B) a linked list allocation C) a continuous allocation D) a linked list with index30) Which traversal method for a binary tree does the following Pascal code illustrate? procedure traverse(p:p

23、ointer); begin if q <> nil then begin traverse(p.left) ; process(p) ; traverse(p.right) ; end end; A) Inorder B) Preorder C) Postorder D) Reorder31) Which of the following is NOT a condition for deadlock? A) Starvation B) Circular Wait C) No Preemption D) Mutual Exclusion32) Assume that an ope

24、rating system uses a round-robin scheduler. The process's quantum is 20msec, and the context switch is 5 msec. What percentage of the CPU's time is spent on administrative overhead? A) 5% B) 15% C) 20% D) 25%33) What state is a process in when it can't run because it needs a resource to

25、become available? A) Ready B) Interrupt C) Blocked D) Running34) The following sectors are requested from the disk: 11,1,36,16,34,9,12 What is the order of the sector reads if you are using the elevator algorithm? A) 1,9,11,12,16,34,36 B) 11,1,36,16,34,9,12 C) 11,12,9,16,1,34,36 D) 11,12,16,34,36,9,

26、135) What is the candidate key of a relational database? A) A field with a constraint placed on it. B) A set of fields that have no data in them. C) A set of fields in a table used to identify a record uniquely. D) Fields from multiple tables that are used for sorting records.36) Which operating sys

27、tem can Oracle database NOT be used in? A) DOS B) UNIX C) Windows95 D) IBM Mainframes37) Which values are NOT permitted to be part of the primary key? A) NULL B) punctuation C) special characters D) alpha-numeric characters38) Which phase of the software engineering process results in the Software R

28、equirements Specification? A) difinition phase B) engineering phase C) maintenance phase D) development phase39) When drawing multilevel data flow chart of top-down, the balance between parent chart and son chart must be taken into account, and to pass judgment for the balance of the charts is regul

29、arly maintained by? A) Output data B) Data dictionary C) Processing number D) Input data40) Which is the strictest form of cohesion? A) logical B) functional C) procedural D) coincidental 41) Which is NOT a concept of White Box Testing? A) You should execute all loops at their boundary conditions. B

30、) You should execute all interfaces at their boundary conditions. C) You should execute all logical decisions on their true and false sides. D) You should execute all independent paths within a module at least once. 42) Prototyping method is a dynamic design process, it requires people who use prototyping method should have the following capability? A) Proficient program expertise B) Immediately acquire requirement C) Coordinate & organize eloquently D)