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) 10B) FC) TD) None of the above2) What is the definition of a PathA) 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) None of the above.3) Which UNIX command creates a symbolic link named myfile in the current directory to the file/etc/hostsA) ln -s /etc/hosts myfileB) ln -s myfile /etc/hostsC) link -s /etc/hosts myfileD) link -s myfile /etc/hosts4) Which MS-DOS command is correctA) DEL /S *.batB) DEL *.exe/SPC) 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 policy0 1 2 3 0 1 4 0 1 2 3 4A) 8B) 9C) 10D) 116) Which element is NOT part of a microkernel?A) basic I/OB) a file systemC) IPC mechanismsD) memory management7) Which is local to a thread instead of a process?A) a stackB) an open fileC) a semaphoresD) an address space8) What is a subselect statement?A) a select statement that selects a subset of fields in a tableB) a select statement that returns a subset of the data in a tableC) a select statement that appears within another select statementD) a select statement that returns a subset of the constraints on a field9) In developing a hospital database, 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 PATIENTand TREATMENT is 1:M. The relationship between PATIENT and BED is 1:1, conditional. If treatmentrecord 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) 6,000B) 4,800C) 18,000D) 1,60010) Which of the following conditions will make a relation that is in first normal from to bein 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) ⅠonlyB) Ⅰand ⅡonlyC) Ⅰand ⅢonlyD) any of them11) The most commonly used locking level in implementing concurrency control is at which of the following levels?A) databaseB) tableC) recordD) field12) 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 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) ReusabilityB) MaintanenceC) ExpansibilityD) Portability14) Which phase of the software development requires the most development time?A) the design phaseB) the testing phaseC) the maintenance phaseD) the development phase15) Black-box and white-box testing method are often used in software testing phase, in which, the white-box is mainly used to test software's?A) reasonableness of structureB) correctness of a programC) external function of a programD) internal logic of a program16) How does Booth's Algorithm improve binary multiplication?A) It prevents overflow.B) It prevents 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) 25B) 60C) 75D) 10018) Which is NOT a characteristic of an RISC processor?A) a high clock speedB) a highly optimized pipelineC) a few general-purpose registersD) a limited amount of small instructions19) You are performing two sums: the first is a sum of two scalar variables and the second isa matrix sum of a pair of two-dimensional arrays-size 1000 by 1000. What speedup is achieved when the calculations are performed on size 1000 processors?A) 50B) 100C) 999D) 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 KbpsB) 9.3 KbpsC) 30.9 KbpsD) 30.17 Kbps21) 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 LayersB) the Physical, Data Link, and Network LayersC) the Physical, Data Link, and Transport LayersD) the Physical, Session, and Presentation Layers22) 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 forward the frame.A) Fixed RoutingB) Spanning TreeC) Source RoutingD) Frame Forwarding23) Which OSI layer does a bridge operate at?A) the Physical LayerB) the Network LayerC) the Transport LayerD) the Data Link Layer24) There are several periods in a computer, the shortest period is?A) Instruction periodB) Machine periodC) Beat periodD) CPU period25) 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 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) SymmetryB) ReflexivityC) AsymmetryD) Antisymmetry27) When walking a tree, which traversal method yields a prefix, or Polish,form?A) InorderB) PreorderC) PostorderD) Reorder28) 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 operation on undirected graph.29) What storage scheme does MS-DOS use for storing files on a disk?A) I-nodesB) a linked list allocationC) a continuous allocationD) a linked list with index30) Which traversal method for a binary tree does the following Pascal code illustrate? procedure traverse(p:pointer);beginif q <> nil then begintraverse(p^.left) ; process(p) ; traverse(p^.right) ;endend;A) InorderB) PreorderC) PostorderD) Reorder31) Which of the following is NOT a condition for deadlock?A) StarvationB) Circular WaitC) No PreemptionD) Mutual Exclusion32) Assume that an operating 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 become available?A) ReadyB) InterruptC) BlockedD) Running34) The following sectors are requested from the disk: 11,1,36,16,34,9,12What is the order of the sector reads if you are using the elevator algorithm?A) 1,9,11,12,16,34,36B) 11,1,36,16,34,9,12C) 11,12,9,16,1,34,36D) 11,12,16,34,36,9,135) 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 system can Oracle database NOT be used in?A) DOSB) UNIXC) Windows95D) IBM Mainframes37) Which values are NOT permitted to be part of the primary key?A) NULLB) punctuationC) special charactersD) alpha-numeric characters38) Which phase of the software engineering process results in the Software Requirements Specification?A) difinition phaseB) engineering phaseC) maintenance phaseD) 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 regularly maintained by?A) Output dataB) Data dictionaryC) Processing numberD) Input data40) Which is the strictest form of cohesion?A) logicalB) functionalC) proceduralD) coincidental41) Which is NOT a concept of White Box Testing?A) You should execute all loops at their boundary conditions.B) 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 expertiseB) Immediately acquire requirementC) Coordinate & organize eloquentlyD) Handle tools smartly43) There are two styles in the evolution of instruction set, that is CISC and RISC. Which chip belongs to the RISC?A) i APX 432B) V AX-11/780C) Motorola 68000D) Power PC44) In advanced PC bus or local bus, which one has the fastest datat throughput?A) ISAB) PCIC) MCAD) EISA45) There are many methods in the CPETT(short for Computer Performance Evaluation Tools andTechniques). One of them is the method that runs a Kernel as the load of a computer. So wecall it?A) Monitor methodB) Benchmark methodC) Model methodD) Physical method46)在Windows中已打开多个应用程序，要找出不在当前屏幕上的应用程序窗口，可以按:A)<Ctrl>+<Del>B)<Ctrl>+<Break>C)<Alt>+<Esc>D)<Alt>+<F4>47)在Windows操作中，如果某个菜单项的颜色暗淡，则表示:A)只要双击，就能选中B)必须连续三击，才能选中C)单击被选中后，还会显示出一个方框要求操作者进一步输入信息D)在当前情况下，这项是没有意义的，选中它不会有任何反应48)下列不是计算机网络的系统结构A)星型结构B)单线结构C)总线结构D)环型结构49)局部地区通信网络简称局域网,英文缩写为:A)W ANB)LANC)SAND)MAN50)下列局域网不提供的服务是A)资源共享B)设备共享C)多媒体通信D)分布式计算答案：CBACB BACDD CABCD CCCCD BCDBD DBCBA ACCDC AAABB BBDBB CDBBD。
