川大软院计网选择题答案Chapter1(含答案)

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四川大学《计算机软件技术基础》2018至2019学年期末试题(一)

四川大学期末考试试题（开卷）（2018——2019学年第 1 学期） A卷课程号：课序号：课程名称：任课教师：成绩：试卷编号：8. 设有如下的单链表的按序号查找的算法，其时间复杂度为（）。

LinkNode *GetNode(Linklist head, int i) {int j;ListNode *p;P = head; j=0;while(p->next && j<i){ p = p->next; j++;}if(i==j)return(p);elsereturn(NULL); }A. O(n2)B. O(n)C. O(n3)D. O(logn)9. 假定一个链式队列的队首和队尾指针分别用front和rear表示，每个结点的结构为：，当出列时所进行的指针操作为（）A. front = front->next;B. rear = rear->next;C. front->next = rear; rear = rear->next;D. front = front->next; front->next = rear;10. 如果进栈序列为e1,e2,e3,e4，则可能的出栈序列是（）。

A. e3，e1，e4，e2B. e2，e4，e3，e1C. e3，e4，e1，e2D. 以上均有可能11. 若用一个大小为6的数组来实现循环队列，且当前rear和front的值分别为0和3。

当从队列中删除一个元素，再加入两个元素后，rear和front的值分别为（）。

A. 1和5B. 2和4C. 4和2D. 5和112. 判断一个顺序栈ST（最多元素为mo）为空的条件是（）。

A. ST->top <> 0B. ST->top == 0C. st->top <> moD. st->top == mo13. 有一个N×N的下三角矩阵A，若采用行优先进行顺序存储，每个元素占用k个字节，则A ij(1≤i ≤N,1≤j≤i)元素的相对字节地址（相对首元素地址而言）为（）A. (i×(i+1)/2+j-1)×4B. (i×i/2+j)×4C. (i×(i-1)/2+j-1)×4D. (i×(i-1)/2+j)×414. 一个数组元素a[i]与（）的表示等价。

川大软院计网选择题答案Chapter4(含答案)

CHAPTER 4: NETWORK LAYER1.Which of the following groups belongs to network layer protocol? _____D____A.IP, TCP and UDPB.ARP, IP, and UDPC.FTP, IMAP and IPD.ICMP, BGP, and RIP2.The 3-PDU is named as ____C_____A.messageB.packetC.datagramD.segment3.In a datagram network, the forwarding decision is based on the value of the____B field in the packet header.A.source addressB.destination addressbelD.None of the choices are4.HOL blocking happens on ____A_____A.input portB.output portC.switching fabricsD.all of above5.If no free buffers in router, the arriving packets will be: AA.droppedB.queuedC.returnedD.marked6.During normal IP packet forwarding at a router, which of the following packetfields are updated? ____C____A.Source IP addressB.Destination IP addressC.ChecksumD.Destination port number7.Which of the following IP address doesn’t belong to the 202.115.32.0/25 network?______D___A.202.115.32.1B.202.115.32.11C.202.115.32.120D.202.115.32.1298.You are given an IP network of 192.168.5.0 and told that you need to separatethis network into sub networks that can support a maximum of 30 hosts per subnet.This will help alleviate congestion on the network. What subnet mask can you use to create the subnets necessary to meet the given criteria? ___C______A.255.255.255.0B.255.255.255.128C.255.255.255.224D.255.255.255.2409.An IP datagram of 1500 bytes (20 byte of IP header plus 1480 bytes of IP payload)arrives at a router and must be forwarded to a link with an MTU of 500 bytes.Thus the router has to fragment the datagram. To the last fragment, the value of offset should be _____D____A.1440B.1000C.186D.18010.IP is a ____C_____ protocol.A.connection-oriented unreliableB.connection-oriented reliableC.connectionless unreliableD.connectionless reliable11.Which ICMP message type is the basis for the Traceroute utility?BA.Echo RequestB.TTL expiredC.Host UnreachableD.Fragment Reassembly Time Exceed12.Routers in the path are not allowed to _________________B__________.A.fragment the packet they receiveB.change source or destination addressC.decapsulate the packetD.All of the choices are correct13.____B_____ allows a site to use a set of private addresses for internalcommunication and a set of global Internet addresses for communication with the rest of the world.A.DHCPB.NATC.ICMPD.None of the choices are correct14.How many bits are there in IPv6 ? ______C___A.32B.64C.128D.25615.In CIDR notation, which of the following networks contains host 192.168.14.2?CA.192.168.10.0/22B.192.168.11.0/21C.192.168.12.0/23D.192.168.13.0/2416.What is the limited broadcast address corresponding to the node with thefollowing IP address: 131.15.46.59?DA.131.15.46.255B.131.15.255.255C.255.255.255.255D.None of the above17.In classful IP addressing, how many network bits does 125.140.128.16 have?AA.8B.16C.24D.3218.What is the broadcast IP address for 193.140.141.128 / 26 ?DA.193.140.141.128B.193.140.141.127C.255.255.255.63D.193.140.141.19119.What’s a network? From IP address perspective they can physically reach eachother without intervening router and the device interfaces with: CA.same IP addressB.same TCP port #C.same network part of IP addressD.same host part of IP address20.The Internet’s network layer has three major components, the first component isthe IP protocol, the second component is the routing protocol, the final component is____.DA.forwardingB.address translationC.checkD.ICMP21.IP addressing assigns an address to 223.10.198.250/29, the network address forthis network is____.A（）A.223.10.198.248B.223.10.198.250C.223.10.198.0D.223.10.0.022.There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Theirchecksum isA____.A.0100010001000011B.1011101110111100C.1111111111111111D.100000000000000023.The use of hierarchy in routing tables can __A______ the size of the routingtables.A.reduceB.increaseC.neither reduce nor increaseD.None of the choices are correct24.Which of the following protocol doesn’t belong to intra-AS routing protocol?_____B____A.RIPB.BGPC.OSPFD.IRAP25.Which of the following protocol belongs to intra-AS routing protocol?______A___A.RIPB.BGPC.DV (Distance Vector)D.LS (Link State)26.In OSPF network, a ____B_____ belongs to both an area and the backbone.A.internal routerB.area border routerC.boundary routerD.backbone router27._A___ is an inter-domain routing protocol using path vector routing.A.BGPB.RIPC.OSPFD.None of the choices are correct28.RIP uses the services of ___C____.A.TCPB.IPC.UDPD.None of the choices are correct29.The Routing Information Protocol (RIP) is an intra-domain routing based on_______A__ routing.A.distance vectorB.link stateC.path vectorD.all of the above30.Which of the following algorithm has the so called count-to-infinity problem?CA.Flooding algorithmB.Link-state algorithmC.Distance vector algorithmD.None of the above。

川大软院计网选择题答案Chapter1(含答案)

1.1 In the following options, which does not define in protocol? ( D )A the format of messages exchanged between two or more communicatingentitiesB the order of messages exchanged between two or more communicatingentitiesC the actions taken on the transmission of a message or other eventD the transmission signals are digital signals or analog signals1.2 In the following options, which is defined in protocol? ( A )A the actions taken on the transmission and/or receipt of a message or othereventB the objects exchanged between communicating entitiesC the content in the exchanged messagesD the location of the hosts1.3 An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes (C ).A flow controlB congestion-controlC reliable data transferD connection-oriented service1.4 The Internet’s connection-oriented service has a name, it is ( A ).A TCPB UDPC TCP/IPD IP1.5 The Internet’s connectionless service is called ( B ).A TCPB UDPC TCP/IPD IP1.6 Which of the following nodes belongs to the network core?CA. a Web ServerB. a Host with Win2003 ServerC. a Router with NAT serviceD. a Supernode on Skype Network1.7 In the Internet, the equivalent concept to end systems is ( )A.A hostsB serversC clientsD routers1.8 In the Internet, end systems are connected together by ( C ).A copper wireB coaxial cableC communication linksD fiber optics1.9 End systems access to the Internet through its (C ).A modemsB protocolsC ISPD sockets1.10 In the following options, which belongs to the network core? ( B )A end systemsB routersC clientsD servers1.11 End systems, packet switches, and other pieces of the Internet, run ( D ) that control the sending and receiving of information within the Internet.A programsB processesC applicationsD protocols1.12 The internet allows ( D ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications1.13 The protocols of various layers are called ( A ).A the protocol stackB TCP/IPC ISPD network protocol1.14 In the OSI reference model, the upper layers of the OSI model are, in correct orderDA Session, application, presentationB Session, presentation, applicationC Session, application, presentation, physicalD Application, presentation, session1.15 The lower layers of the OSI model are, in correct orderDA physical, system, network, logicalB physical, logical, network, systemC physical, transport, network, data linkD physical, data link, network, transport1.16 The Internet Protocol (IP) generally corresponds to which OSI layer?AA Network (layer three)B Transport (layer four)C Data link (layer two)D Session (layer five)1.17 What layer of the OSI model is designed to perform error detection functions?BA PhysicalB Data linkC NetworkD transport1.18 Which of the following protocol layers is not explicitly part of the Internet Protocol Stack? _____B____A. application layerB. session layerC. data link layerD. transport layer1.19 The 5-PDU is called__A_A. messageB. segmentC. datagramD. frame1.20 The Internet’s network layer is responsible for moving network-layer packets known as B( ) from one host to another.A frameB datagramC segmentD message1.21 Transport-layer packets are called:BA. messageB. segmentC. datagramD. frame1.22 The units of data exchanged by a link-layer protocol are called ( A).A FramesB SegmentsC DatagramsD bit streams1.23 There are two fundamental approaches to building a network core, ( B ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching1.24 Datagram networks and virtual-circuit networks differ in that ( C ).A datagram networks are circuit-switched networks, and virtual-circuitnetworks are packet-switched networks.B datagram networks are packet-switched networks, and virtual-circuitnetworks are circuit-switched networks.C datagram networks use destination addresses and virtual-circuit networks useVC. numbers to forward packets toward their destination.D datagram networks use VC. numbers and virtual-circuit networks usedestination addresses to forward packets toward their destination.1.25 (A ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM1.26 In ( C ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.A packet-switchedB data-switchedC circuit-switchedD message-switched1.27 In ( A ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link.A packet-switchedB data-switchedC circuit-switchedD message-switched1.28 In a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( A) of the link’s bandwidth for the duration of the connection.A a fraction 1/nB allC 1/2D n times1.29 For (C ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot.A CDMAB packet-switched networkC TDMD FDM1.30 The network that forwards packets according to host destination addresses is called ( D) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram1.31 The network that forwards packets according to virtual-circuit numbers is called ( C ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram1.32 The time required to propagate from the beginning of the link to the next router is ( C).A queuing delayB processing delayC propagation delayD transmission delay1.33 Processing delay does not include the time to (B ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet1.34 In the following four descriptions, which one is correct? ( C)A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensity decreases.C If the traffic intensity is close to zero, the average queuing delay will be closeto zero.D If the traffic intensity is close to one, the average queuing delay will be closeto one.1.35 Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( B ),A LR／aB La／RC Ra／LD LR／a1.36 Suppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 and R2, respectively. Assuming that the switch uses store-and-forward packet switching, what is the total end-to-end delay to send a packet of length L? (Ignore queuing delay, propagation delay, and processing delay.) ( A )A L/R1＋L/R2B L/R1C L/R2D none of the above1.37 We are sending a 30 Mbit MP3 file from a source host to a destination host. Suppose there is only one link between source and destination and the link has a transmission rate of 10 Mbps. Assume that the propagation speed is 2 * 108 meters/sec, and the distance between source and destination is 10,000 km. Also suppose that message switching is used, with the message consisting of the entire MP3 file. How many bits will the source have transmitted when the first bit arrives at the destination?CA. 1 bitB. 30,000,000 bitsC. 500,000 bitsD. none of the above1.38 In the following entries, which is not a kind of access network?(D )A residential accessB company accessC wireless accessD local access1.39 The following technologies may be used for residential access, exceptDA. HFCB. DSLC. Dial-up modemD. FDDI1.40 Which kind of media is not a guided media? ( D)A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel。

川大软件数据结构选择题库

_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库一Chapter 1 Data Structures and Algorithms: Instructor's CD questions1.The primary purpose of most computer programs isa)to perform a mathematical calculation.*b) to store and retrieve information.c)to sort a collection of records.d)all of the above.e)none of the above.2.An integer is aa)) simple typeb)aggregate typec)composite typed)a and be)none of the above3.A payroll records is aa)simple typeb)aggregate typec)composite type*d) a and b e) none of the above4.Which of the following should NOT be viewed as an ADT?a)listb)integerc)array*d) none of the above5.A mathematical function is most like a*a) Problemb)Algorithmc)Program6.An algorithm must be or do all of the following EXCEPT:a)correctb)composed of concrete steps*c) ambiguousd)composed of a finite number of stepse)terminate7.A solution is efficient ifa.it solves a problem within the require resource constraints.b.it solves a problem within human reaction time.1_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库_______ c.it solves a problem faster than other known solutions.d.a and b.*e. a and c.f. b and c.8.An array isa)A contiguous block of memory locations where each memory location storesa fixed-length data item.b)An ADT composed of a homogeneous collection of data items, each data item identified by a particular number.c)a set of integer values.*d) a and b.e)a and c.f)b and c.9.Order the following steps to selecting a data structure to solve a problem.(1)Determine the basic operations to be supported.(2)Quantify the resource constraints for each operation.(3)Select the data structure that best meets these requirements.(4)Analyze the problem to determine the resource constraints that anysolution must meet.a)(1, 2, 3, 4)b)(2, 3, 1, 4)c)(2, 1, 3, 4)*d) (1, 2, 4, 3)e) (1, 4, 3, 2)10.Searching for all those records in a database with key value between 10 and 100 is known as:a) An exact match query.*b) A range query.c)A sequential search.d)A binary search.Chapter 2 Mathematical Preliminaries: Instructor's CD questions1.A set has the following properties:a)May have duplicates, element have a position.b)May have duplicates, elements do not have a position.c)May not have duplicates, elements have a position.*d) May not have duplicates, elements do not have a position._______________________________ 少年易学老难成，一寸光阴不可轻-百度文库2.A sequence has the following properties:a)) May have duplicates, element have a position.b)May have duplicates, elements do not have a position.c)May not have duplicates, elements have a position.d)May not have duplicates, elements do not have a position.3.For set F, the notation |P| indicatesa)) The number of elements in Pb)The inverse of Pc)The powerset of F.d)None of the above.4.Assume that P contains n elements. The number of sets in the powerset of P isa)nb)n A2*c) 2A nd)2A n - 1e) 2A n + 15.If a sequence has n values, then the number of permutations for that sequence will bea)nb)n A2c)n A2 - 1d)2A n*e) n!6.If R is a binary relation over set S, then R is reflexive if*a) aRa for all a in S.b)whenever aRb, then bRa, for all a, b in S.c)whenever aRb and bRa, then a = b, for all a, b in S.d)whenever aRb and aRc, then aRc, for all a, b, c in S.7.If R is a binary relation over set S, then R is transitive ifa)aRa for all a in S.b)whenever aRb, then bRa, for all a, b in S.c)whenever aRb and bRa, then a = b, for all a, b in S.*d) whenever aRb and aRc, then aRc, for all a, b, c in S.8.R is an equivalence relation on set S if it isa)) reflexive, symmetric, transitive.b)reflexive, antisymmetric, transitive.c)symmetric, transitive.少年易学老难成，一寸光阴不可轻-百度文库d)antisymmetric, transitive.e)irreflexive, symmetric, transitive.f)irreflexive, antisymmetric, transitive.9.For the powerset of integers, the subset operation defines *a) a partial order.b)a total order.c)a transitive order.d)none of the above.10.log nm is equal toa) n + m*b) log n + log mc)m log nd)log n - log m11.A close-form solution isa) an analysis for a program.*b) an equation that directly computes the value of a summation.c) a complete solution for a problem.12.Mathematical induction is most likea) iteration.*b) recursion.c)branching.d)divide and conquer.13.A recurrence relation is often used to model programs witha)for loops.b)branch control like "if" statements.*c) recursive calls.d) function calls.14.Which of the following is not a good proof technique.a) proof by contradiction.*b) proof by example.c) proof by mathematical induction.15.We can use mathematical induction to:a) Find a closed-form solution for a summation.*b) Verify a proposed closed-form solution for a summation.c) Both find and verify a closed-form solution for a summation._______________________________ 少年易学老难成，一寸光阴不可轻-百度文库一Chapter 3 Algorithm Analysis: Instructor's CD questions1.A growth rate applies to:a)the time taken by an algorithm in the average case.b)the time taken by an algorithm as the input size grows.c)the space taken by an algorithm in the average case.d)the space taken by an algorithm as the input size grows.e)any resource you wish to measure for an algorithm in the average case.*f) any resource you wish to measure for an algorithm as the input size grows.2.Pick the growth rate that corresponds to the most efficient algorithm as n gets large:a) 5n*b) 20 log nc)2nA2d)2A n3.Pick the growth rate that corresponds to the most efficient algorithm when n =4.a)5nb)20 log nc)2nA2*d)2A n4.Pick the quadratic growth rate.a)5nb)20 log n*c) 2nA2d) 2An5.Asymptotic analysis refers to:a) The cost of an algorithm in its best, worst, or average case.*b) The growth in cost of an algorithm as the input size grows towards infinity.c)The size of a data structure.d)The cost of an algorithm for small input sizes6.For an air traffic control system, the most important metric is:a)The best-case upper bound.b)The average-case upper bound.c)) The worst-case upper bound.d)The best-case lower bound._______________________________ 少年易学老难成，一寸光阴不可轻-百度文库__________e)The average-case lower bound.f)The worst-case lower bound.7.When we wish to describe the upper bound for a problem we use:a)) The upper bound of the best algorithm we know.b)The lower bound of the best algorithm we know.c)We can't talk about the upper bound of a problem because there can alwaysbe an arbitrarily slow algorithm.8.When we describe the lower bound for a problem we use:a)The upper bound for the best algorithm we know.b)the lower bound for the best algorithm we know.c)The smallest upper bound that we can prove for the best algorithm that could possibly exist.*d) The greatest lower bound that we can prove for the best algorithm that could possibly exist.9.When the upper and lower bounds for an algorithm are the same, we use:a)big-Oh notation.b)big-Omega notation.*c) Theta notation.d)asymptotic analysis.e)Average case analysis.f)Worst case analysis.10. When performing asymptotic analysis, we can ignore constants and low order terms because:*a) We are measuring the growth rate as the input size gets large.b)We are only interested in small input sizes.c)We are studying the worst case behavior.d)We only need an approximation.11.The best case for an algorithm refers to:a) The smallest possible input size.*b) The specific input instance of a given size that gives the lowest cost.c)The largest possible input size that meets the required growth rate.d)The specific input instance of a given size that gives the greatest cost.12.For any algorithm:a)) The upper and lower bounds always meet, but we might not know what they are.少年易学老难成，一寸光阴不可轻-百度文库b)The upper and lower bounds might or might not meet.c)We can always determine the upper bound, but might not be able to determine the lower bound.d)We can always determine the lower bound, but might not be able to determine the upper bound.13.If an algorithm is Theta(f(n)) in the average case, then it is: a) Omega(f(n)) in the best case.*b) Omega(f(n)) in the worst case.c) O(f(n)) in the worst case.14.For the purpose of performing algorithm analysis, an important property ofa basic operation is that:a)It be fast.b)It be slow enough to measure.c)Its cost does depend on the value of its operands.*d) Its cost does not depend on the value of its operands.15.For sequential search,a) The best, average, and worst cases are asymptotically the same.*b) The best case is asymptotically better than the average and worst cases.c)The best and average cases are asymptotically better than the worst case.d)The best case is asymptotically better than the average case, and the average case is asymptotically better than the worst case.Chapter 4 Lists, Stacks and Queues: Instructor's CD questions1.An ordered list is one in which:a) The element values are in sorted order.*b) Each element a position within the list.2.An ordered list is most like a:a)set.b)bag.c)) sequence.3.As compared to the linked list implementation for lists, the array-based listimplementation requires:a)More spaceb)Less space*c) More or less space depending on how many elements are in the list._______________________________ 少年易学老难成，一寸光阴不可轻-百度文库4.Here is a series of C++ statements using the list ADT in the book.L1.append(10);L1.append(20);L1.append(15);If these statements are applied to an empty list, the result will look like:a)< 10 20 15 >*b) < | 10 20 15 >c)< 10 20 15 | >d)< 15 20 10 >e)< | 15 20 10 >f)< 15 20 10 | >5.When comparing the array-based and linked implementations, the array-based implementation has:a)) faster direct access to elements by position, but slower insert/delete from the current position.b)slower direct access to elements by position, but faster insert/delete from the current position.c)both faster direct access to elements by position, and faster insert/delete from the current position.d)both slower direct access to elements by position, and slower insert/delete from the current position.6.For a list of length n, the linked-list implementation's prev function requiresworst-case time:a)O(1).b)O(log n).*c) O(n).d) O(n A2).7.Finding the element in an array-based list with a given key value requiresworst case time:a)O(1).b)O(log n).*c) O(n).d) O(n A2).8.In the linked-list implementation presented in the book, a header node isused:*a) To simplify special cases._______________________________ 少年易学老难成，一寸光阴不可轻-百度文库一b)Because the insert and delete routines won't work correctly without it.c)Because there would be no other way to make the current pointer indicatethe first element on the list.9.When a pointer requires 4 bytes and a data element requires 4 bytes, thelinked list implementation requires less space than the array-based list implementation when the array would be:a)less than 1/4 full.b)less than 1/3 full.*c) less than half full.d)less than 第full.e)less than 34 fullf)never.10.When a pointer requires 4 bytes and a data element requires 12 bytes, thelinked list implementation requires less space than the array-based list implementation when the array would be:a)) less than 1/4 full.b)less than 1/3 full.c)less than half full.d)less than 2/3 full.e)less than 34 fullf)never.11.When we say that a list implementation enforces homogeneity, we meanthat:a) All list elements have the same size.*b) All list elements have the same type.c) All list elements appear in sort order.12.When comparing the doubly and singly linked list implementations, we findthat the doubly linked list implementation*a) Saves time on some operations at the expense of additional space.b)Saves neither time nor space, but is easier to implement.c)Saves neither time nor space, and is also harder to implement.13. We use a comparator function in the Dictionary class ADT:a)to simplify implementation.*b) to increase the opportunity for code reuse.c) to improve asymptotic efficiency of some functions.14.All operations on a stack can be implemented in constant time except:少年易学老难成，一寸光阴不可轻-百度文库a) Pushb)Popc)The implementor's choice of push or pop (they cannot both be implementedin constant time).*d) None of the above.15.Recursion is generally implemented usinga) A sorted list.*b) A stack.c) A queue.Chapter 5 Binary Trees: Instructor's CD questions1.The height of a binary tree is:a)The height of the deepest node.b)The depth of the deepest node.*c) One more than the depth of the deepest node.2.A full binary tree is one in which:*a) Every internal node has two non-empty children.b) all of the levels, except possibly the bottom level, are filled.3.The relationship between a full and a complete binary tree is:a)Every complete binary tree is full.b)Every full binary tree is complete.*c) None of the above.4.The Full Binary Tree Theorem states that:a)) The number of leaves in a non-empty full binary tree is one more than the number of internal nodes.b)The number of leaves in a non-empty full binary tree is one less than the number of internal nodes.c)The number of leaves in a non-empty full binary tree is one half of the number of internal nodes.d)The number of internal nodes in a non-empty full binary tree is one half of the number of leaves.5.The correct traversal to use on a BST to visit the nodes in sorted order is:a) Preorder traversal.*b) Inorder traversal.c) Postorder traversal.6. When every node of a full binary tree stores a 4-byte data field,10少年易学老难成，一寸光阴不可轻-百度文库two 4-byte child pointers, and a 4-byte parent pointer, theoverhead fraction is approximately:a)one quarter.b)one third.c)one half.d)two thirds.*e) three quarters.f) none of the above.7.When every node of a full binary tree stores an 8-byte data field and two 4-byte child pointers, the overhead fraction is approximately:a)one quarter.b)one third.*c) one half.d)two thirds.e)three quarters.f)none of the above.8.When every node of a full binary tree stores a 4-byte data field and theinternal nodes store two 4-byte child pointers, the overhead fraction is approximately:a)one quarter.b)one third.*c) one half.d)two thirds.e)three quarters.f)none of the above.9.If a node is at position r in the array implementation for a complete binarytree, then its parent is at:a)) (r - 1)/2 if r > 0b)2r + 1 if (2r + 1) < nc)2r + 2 if (2r + 2) < nd)r - 1 if r is evene)r + 1 if r is odd.10.If a node is at position r in the array implementation for a complete binarytree, then its right child is at:a)(r - 1)/2 if r > 0b)2r + 1 if (2r + 1) < n*c) 2r + 2 if (2r + 2) < nd)r - 1 if r is evene)r + 1 if r is odd.11_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库—11.Assume a BST is implemented so that all nodes in the left subtree of agiven node have values less than that node, and all nodes in the rightsubtree have values greater than or equal to that node. Whenimplementing the delete routine, we must select as its replacement:a) The greatest value from the left subtree.*b) The least value from the right subtree.c) Either of the above.12.Which of the following is a true statement:a)In a BST, the left child of any node is less than the right child, and in a heap, the left child of any node is less than the right child.*b) In a BST, the left child of any node is less than the right child, but in a heap, the left child of any node could be less than or greater than the right child.c)In a BST, the left child of any node could be less or greater than the right child, but in a heap, the left child of any node must be less than the right child.d)In both a BST and a heap, the left child of any node could be either less than or greater than the right child.13.When implementing heaps and BSTs, which is the best answer?a)The time to build a BST of n nodes is O(n log n), and the time to build a heap of n nodes is O(n log n).b)The time to build a BST of n nodes is O(n), and the time to build a heap of n nodes is O(n log n).*c) The time to build a BST of n nodes is O(n log n), and the time to build a heap of n nodes is O(n).d) The time to build a BST of n nodes is O(n), and the time to build a heap of n nodes is O(n).14.The Huffman coding tree works best when the frequencies for letters area) Roughly the same for all letters.*b) Skewed so that there is a great difference in relative frequencies for various letters.15.Huffman coding provides the optimal coding when:a)The messages are in English.b)The messages are binary numbers.*c) The frequency of occurrence for a letter is independent of its context within the message.d) Never.12_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库一Chapter 6 Binary Trees: Instructor's CD questions1.The primary ADT access functions used to traverse a general tree are: a) left child and right siblingb) left child and right child*c) leftmost child and right siblingd) leftmost child and next child2.The tree traversal that makes the least sense for a general treeis:a) preorder traversal*b) inorder traversalc) postorder traversal3.The primary access function used to navigate the general tree when performing UNION/FIND is:a)left childb)leftmost childc)right childd)right sibling*e) parent4.When using the weighted union rule for merging disjoint sets, the maximum depth for any node in a tree of size n will be:a) nearly constant*b) log nc)nd)n log ne)n A25.We use the parent pointer representation for general trees to solve which problem?a)Shortest pathsb)General tree traversal*c) Equivalence classesd) Exact-match query6. When using path compression along with the weighted union rule for merging disjoint sets, the average cost for any UNION or FIND operation in a tree of size n will be:*a) nearly constantb)log nc)nd)n log n13_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库一7.The most space efficient representation for general trees will typically be:a) List of children*b) Left-child/right siblingc) A K-ary tree.8.The easiest way to represent a general tree is to:a) convert to a list.*b) convert to a binary tree.c) convert to a graph.9.As K gets bigger, the ratio of internal nodes to leaf nodes:a)) Gets smaller.b)Stays the same.c)Gets bigger.d)Cannot be determined, since it depends on the particular configuration of the tree.10.A sequential tree representation is best used for:*a) Archiving the tree to disk.b)Use in dynamic in-memory applications.c)Encryption algorithms.d)It is never better than a dynamic representation.Chapter 7 Internal Sorting: Instructor's CD questions1.A sorting algorithm is stable if it:a) Works for all inputs.*b) Does not change the relative ordering of records with identical key values.c) Always sorts in the same amount of time (within a constant factor) for a given input size.2.Which sorting algorithm does not have any practical use?a) Insertion sort.*b) Bubble sort.c)Quicksort.d)Radix Sort.e)a and b.3.When sorting n records, Insertion sort has best-case cost:a)O(log n).14_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库*b) O(n).c)O(n log n).e)O(n!)f)None of the above.4.When sorting n records, Insertion sort has worst-case cost:a)O(log n).b)O(n).c)O(n log n).*d) O(n A2)e)O(n!)f)None of the above.5.When sorting n records, Quicksort has worst-case cost:a)O(log n).b)O(n).c)O(n log n).*d) O(n A2)e)O(n!)f)None of the above.6.When sorting n records, Quicksort has average-case cost:a)O(log n).b)O(n).c)) O(n log n).d)O(n A2)e)O(n!)f)None of the above.7.When sorting n records, Mergesort has worst-case cost:a)O(log n).b)O(n).*c) O(n log n).d)O(n A2)e)O(n!)f)None of the above.8.When sorting n records, Radix sort has worst-case cost:a)O(log n).b)O(n).c)O(n log n).d)O(n A2)e)O(n!)15少年易学老难成，一寸光阴不可轻-百度文库*f) None of the above.9.When sorting n records with distinct keys, Radix sort has a lower bound of:a)Omega(log n).b)Omega(n).*c) Omega(n log n).d)Omega(n A2)e)Omega(n!)f)None of the above.10.Any sort that can only swap adjacent records as an average case lower bound of:a)Omega(log n).b)Omega(n).c)Omega(n log n).*d) Omega(n A2)e)Omega(n!)f)None of the above.11.The number of permutations of size n is:a)O(log n).b)O(n).c)O(n log n).d)O(n A2)*e) O(n!)f)None of the above.12.When sorting n records, Selection sort will perform how many swaps in the worst case?a) O(log n).*b) O(n).c)O(n log n).d)O(n A2)e)O(n!)f)None of the above.13.Shellsort takes advantage of the best-case behavior of which sort?*a) Insertion sortb)Bubble sortc)Selection sortd)Shellsorte)Quicksortf)Radix sort16_______________________________ 少年易学老难成，一寸光阴不可轻-百度文库_______________14.A poor result from which step causes the worst-case behavior for Quicksort?*a) Selecting the pivotb)Partitioning the listc)The recursive call15.In the worst case, the very best that a sorting algorithm can do when sorting n records is:a)O(log n).b)O(n).*c) O(n log n).d)O(n A2)e)O(n!)f)None of the above.Chapter 8 File Processing and External Sorting: Instructor's CD questions1.As compared to the time required to access one unit of data frommain memory, accessing one unit of data from disk is:a)10 times faster.b)1000 times faster.c)1,000,000 time faster.d)10 times slower.e)1000 times slower.*f) 1,000,000 times slower.2.The most effective way to reduce the time required by a disk-based program is to:a) Improve the basic operations.*b) Minimize the number of disk accesses.c)Eliminate the recursive calls.d)Reduce main memory use.3.The basic unit of I/O when accessing a disk drive is:a)A byte.*b) A sector.c)A cluster.d)A track.e)An extent.4.The basic unit for disk allocation under DOS or Windows is:a)A byte.b)A sector.*c) A cluster.17少年易学老难成，一寸光阴不可轻-百度文库d) A track.e) An extent.5.The most time-consuming part of a random access to disk is usually: *a) The seek.b)The rotational delay.c)The time for the data to move under the I/O head.6.The simplest and most commonly used buffer pool replacement strategy is:a)First in/First out.b)Least Frequently Used.*c) Least Recently Used.7.The C++ programmer's view of a disk file is most like:a)) An array.b)A list.c)A tree.d)A heap.8.In external sorting, a run is:a)) A sorted sub-section for a list of records.b)One pass through a file being sorted.c)The external sorting process itself.9.The sorting algorithm used as a model for most external sorting algorithms is:a)Insertion sort.b)Quicksort.*c) Mergesort.d) Radix Sort.10.Assume that we wish to sort ten million records each 10 bytes long (for a total file size of 100MB of space). We have working memory of size 1MB, broken into 1024 1K blocks. Using replacement selection and multiway merging, we can expect to sort this file using how many passes through the file?a)About 26 or 27 (that is, log n).b)About 10.c)4.*d) 2.Chapter 9 Searching: Instructor's CD questions18少年易学老难成，一寸光阴不可轻-百度文库1.Which is generally more expensive?a) A successful search.*b) An unsuccessful search.2.When properly implemented, which search method is generally the most efficient for exact-match queries?a)Sequential search.b)Binary search.c)Dictionary search.d)Search in self-organizing lists*e) Hashing3.Self-organizing lists attempt to keep the list sorted by:a) value*b) frequency of record accessc) size of record4.The 80/20 rule indicates that:a) 80% of searches in typical databases are successful and 20% are not.*b) 80% of the searches in typical databases are to 20% of the records.c) 80% of records in typical databases are of value, 20% are not.5.Which of the following is often implemented using a self-organizing list? *a) Buffer pool.b)Linked list.c)Priority queue.6.A hash function must:a)) Return a valid position within the hash table.b)Give equal probability for selecting an slot in the hash table.c)Return an empty slot in the hash table.7.A good hash function will:a)Use the high-order bits of the key value.b)Use the middle bits of the key value.c)Use the low-order bits of the key value.*d) Make use of all bits in the key value.8.A collision resolution technique that places all records directlyinto the hash table is called:a)Open hashing.b)Separate chaining.*c) Closed hashing.d) Probe function.19少年易学老难成，一寸光阴不可轻-百度文库9.Hashing is most appropriate for:a)In-memory applications.b)Disk-based applications.*c) Either in-memory or disk-based applications.10.Hashing is most appropriate for:a)) Range queries.b)Exact-match queries.c)Minimum/maximium value queries.11.In hashing, the operation that will likely require more record accesses is: *a) insertb) deleteChapter 10 Indexing: Instructor's CD questions1.An entry-sequenced file stores records sorted by:a)Primary key value.b)Secondary key value.*c) Order of arrival.d) Frequency of access.2.Indexing is:a) Random access to an array.*b) The process of associating a key with the location of a corresponding data record.c) Using a hash table.3.The primary key is:a)) A unique identifier for a record.b)The main search key used by users of the database.c)The first key in the index.4.Linear indexing is good for all EXCEPT:a)Range queries.b)Exact match queries.*c) Insertion/Deletion.d)In-memory applications.e)Disk-based applications.5.An inverted list provides access to a data record from its:a) Primary key.20______________________________ 少年易学老难成，一寸光阴不可轻-百度文库*b) Secondary key.c) Search key.6.ISAM degrades over time because:a) Delete operations empty out some cylinders.*b) Insert operations cause some cylinders to overflow.c) Searches disrupt the data structure.7.Tree indexing methods are meant to overcome what deficiency in hashing? *a) Inability to handle range queries.。

史上最全四川大学软件工程导论选择题题库

史上最全四川大学软件工程导论选择题题库-标准化文件发布号：（9456-EUATWK-MWUB-WUNN-INNUL-DDQTY-KIIChapter 11Which question no longer concerns the modern software engineerA)Why does computer hardware cost so muchB) Why does software take a long time to finishC) Why does it cost so much to develop a piece of softwareD) Why can't software errors be removed from products prior to deliverySection2Software is a product and can be manufactured using the same technologies used for other engineering artifacts.A) TrueB)FalseSection3Software deteriorates rather than wears out becauseA) Software suffers from exposure to hostile environmentsB) Defects are more likely to arise after software has been used oftenC)Multiple change requests introduce errors in component interactionsD) Software spare parts become harder to orderSection4WebApps are a mixture of print publishing and software development, making their development outside the realm of software engineering practice.A) TrueB)FalseSection5Which of the items listed below is not one of the software engineering layersA) ProcessB)ManufacturingC) MethodsD) ToolsSection6Software engineering umbrella activities are only applied during the initial phases of software development projects.A) TrueB)FalseSection7Which of these are the 5 generic software engineering framework activitiesA)communication, planning, modeling, construction, deploymentB) communication, risk management, measurement, production, reviewingC) analysis, designing, programming, debugging, maintenanceD) analysis, planning, designing, programming, testingSection8Planning ahead for software reuse reduces the cost and increases the value of the systems into which they are incorporated.A) TrueB) FalseSection9The essence of software engineering practice might be described as understand the problem, plan a solution, carry out the plan, and examine the result for accuracy.A)TrueB) FalseSection10In agile process models the only deliverable work product is the working program.A) TrueB)FalseSection11A most software development projects are initiated to try to meet some business need.A)TrueB) FalseSection12In general software only succeeds if its behavior is consistent with the objectives of its designers.A) TrueB)FalseChapter 21Which of the following are recognized process flow typesA) Concurrent process flowB) Iterative process flowC) Linear process flowD) Spiral process flowE)both a and cSectionSoftware processes can be constructed out of pre-existing software patterns to best meet the needs of a software project.A)TrueB) FalseSection3Which of these are standards for assessing software processesA) SEIB) SPICEC) ISO 9000D) ISO 9001E)both b and dSectionThe waterfall model of software development isA) A reasonable approach when requirements are well defined.B) A good approach when a working program is required quickly.C) The best approach to use for projects with large development teams.D) An old fashioned model that is rarely used any more.SectionThe incremental model of software development isA) A reasonable approach when requirements are well defined.B) A good approach when a working core product is required quickly.C) The best approach to use for projects with large development teams.D) A revolutionary model that is not used for commercial products.SectionEvolutionary software process modelsA) Are iterative in natureB) Can easily accommodate product requirements changesC) Do not generally produce throwaway systemsD)All of the aboveSectionThe prototyping model of software development isA) A reasonable approach when requirements are well defined.B) A useful approach when a customer cannot define requirements clearly.C) The best approach to use for projects with large development teams.D) A risky model that rarely produces a meaningful product.SectionThe spiral model of software developmentA) Ends with the delivery of the software productB) Is more chaotic than the incremental modelC)Includes project risks evaluation during each iterationD) All of the aboveSectionThe concurrent development model isA) Another name for concurrent engineering.B) Defines events that trigger engineering activity state transitions.C) Only used for development of parallel or distributed systems.D) Used whenever a large number of change requests are anticipated.E)both a and bSectionThe component-based development model isA) Only appropriate for computer hardware design.B) Not able to support the development of reusable components.C)Dependent on object technologies for support.D) Not cost effective by known quantifiable software metrics.SectionThe formal methods model of software development makes use of mathematical methods toA) Define the specification for computer-based systemsB) Develop defect free computer-based systemsC) Verify the correctness of computer-based systemsD)All of the aboveSectionWhich of these is not one of the phase names defined by the Unified Process model for software developmentA) Inception phaseB) Elaboration phaseC) Construction phaseD)Validation phaseSectionWhich of these is not a characteristic of Personal Software ProcessA) Emphasizes personal measurement of work productB)Practitioner requires careful supervision by the project managerC) Individual practitioner is responsible for estimating and schedulingD) Practitioner is empowered to control quality of software work products SectionWhich of these are objectives of Team Software ProcessA) Accelerate software process improvementB) Allow better time management by highly trained professionalsC) Build self-directed software teamsD) Show managers how to reduce costs and sustain qualityE)both b and cSection15Process technology tools allow software organizations to compress schedules by skipping unimportant activities.A) TrueB)FalseSection16It is generally accepted that one cannot have weak software processes and create high quality end products.A)TrueB) FalseChapter 3.1Agility is nothing more than the ability of a project team to respond rapidly to change.A) TrueB)FalseSection2Which of the following is not necessary to apply agility to a software processA)Eliminate the use of project planning and testingB) Only essential work products are producedC) Process allows team to streamline tasksD) Uses incremental product delivery strategySection3How do you create agile processes to manage unpredictabilityA) Requirements gathering must be conducted very carefullyB) Risk analysis must be conducted before planning takes placeC) Software increments must be delivered in short time periodsD) Software processes must adapt to changes incrementallyE)both c and dSection4In agile software processes the highest priorities is to satisfy the customer through early and continuous delivery of valuable software.A)TrueB) FalseSectionWhich of the following traits need to exist among the members of an agile software teamA) CompetenceB) Decision-making abilityC) Mutual trust and respectD)All of the aboveSectionIn agile development it is more important to build software that meets the customers' needs today than worry about features that might be needed in the future.A)TrueB) FalseSectionWhat are the four framework activities found in the Extreme Programming (XP) process modelA) analysis, design, coding, testingB) planning, analysis, design, codingC) planning, analysis, coding, testingD)planning, design, coding, testingSection8All agile process models conform to a greater or lesser degree to the principles stated in the "Manifesto for Agile Software Development".A)TrueB) FalseSectionWhat are the three framework activities for the Adaptive Software Development (ASD) process modelA) analysis, design, codingB) feasibility study, functional model iteration, implementationC) requirements gathering, adaptive cycle planning, iterative developmentD)speculation, collaboration, learningSectionWhich is not one of the key questions that is answered by each team member at each daily Scrum meetingA) What did you do since the last meetingB) What obstacles are you encounteringC)What is the cause of the problems you are encounteringD) What do you plan to accomplish be the next team meetingSectionThe Dynamic Systems Development Method (DSDM) suggests a philosophy that is based on the Pareto principle (80% of the application can be delivered in 20% of the time required to build the complete application).A)TrueB) FalseSectionIn Feature Driven Development (FDD) a client-valued feature is a client-valued function that can be delivered in two weeks or less.A) TrueB)FalseSectionAgile Modeling (AM) provides guidance to practitioner during which of these software tasksA) AnalysisB) DesignC) CodingD) TestingE)both a and bSectionAgile Unified Process uses the classic UP phased activities (inception, elaboration, construction, transition) to help the team visualize the overall process flow.A)TrueB) FalseChapter 41Software engineering principles have about a three year half-life.A) TrueB)FalseSection2Which of the following is not one of core principles of software engineering practiceA) All design should be as simple as possible, but no simplerB) A software system exists only to provide value to its users.C)Pareto principle (20% of any product requires 80% of the effort)D) Remember that you produce others will consumeSectionEvery communication activity should have a facilitator to make sure that the customer is not allowed to dominate the proceedings.A) TrueB)FalseSectionThe agile view of iterative customer communication and collaboration is applicable to all software engineering practice.A)TrueB) FalseSectionOne reason to involve everyone on the software team in the planning activity is toA) adjust the granularity of the planB) control feature creepC)get all team members to "sign up" to the planD) understand the problem scopeSectionProject plans should not be changed once they are adopted by a team.A) TrueB)FalseSectionRequirements models depict software in which three domainsA) architecture, interface, componentB) cost, risk, scheduleC)information, function, behaviorD) None of the aboveSectionThe design model should be traceable to the requirements modelA)TrueB) FalseSectionTeams using agile software practices do not generally create models.A) TrueB)FalseSectionWhich of the following is not one of the principles of good codingA) Create unit tests before you begin codingB) Create a visual layout that aids understandingC) Refractor the code after you complete the first coding passD)Write self-documenting code, not program documentationSectionA successful test I ones that discovers at least one as-yet undiscovered error.A)TrueB) FalseSectionWhich of the following are valid reasons for collecting customer feedback concerning delivered softwareA) Allows developers to make changes to the delivered incrementB) Delivery schedule can be revised to reflect changesC) Developers can identify changes to incorporate into next incrementD)All of the aboveChapter 51Requirements engineering is a generic process that does not vary from one software project to another.A)TrueB) FalseSection2During project inception the intent of the of the tasks are to determineA) basic problem understandingB) nature of the solution neededC) people who want a solutionD) none of the aboveE)a, b, and cSection3Three things that make requirements elicitation difficult are problems ofA) budgetingB) scopeC) understandingD) volatilityE)b, c, and dSectionA stakeholder is anyone who will purchase the completed software system under development.A) TrueB)FalseSectionIt is relatively common for different customers to propose conflicting requirements, each arguing that his or her version is the right one.A)TrueB) FalseSectionWhich of the following is not one of the context-free questions that would be used during project inceptionA) What will be the economic benefit from a good solutionB) Who is behind the request for workC)Who will pay for the workD) Who will use the solutionSectionIn collaborative requirements gathering the facilitatorA) arranges the meeting placeB) can not be a customerC)controls the meetingD) must be an outsiderSectionWhich of the following is not one of the requirement classifications used in Quality Function Deployment (QFD)A) excitingB) expectedC)mandatoryD) normalSectionThe work products produced during requirement elicitation will vary depending on theA) size of the budgetB)size of the product being builtC) software process being usedD) stakeholders needsSection10Developers and customers create use-cases to help the software team understand how different classes of end-users will use functions.A)TrueB) FalseSection11Use-case actors are always people, never system devices.A) TrueB)FalseSection12The result of the requirements engineering task is an analysis model that defines which of the following problem domain(s)A) informationB) functionalC) behavioralD)all of the aboveSectionAnalysis patterns facilitate the transformation of the analysis model into a design model by suggesting reliable solutions to common problems.A)TrueB) FalseSection14In win-win negotiation, the customer's needs are met even though the developer's need may not be.A) TrueB)FalseSection15In requirements validation the requirements model is reviewed to ensure its technical feasibility.A) TrueB)FalseChapter 61Which of these is not an element of a requirements modelA) Behavioral elementsB) Class-based elementsC)Data elementsD) Scenario-based elementsSectionWhich of the following is not an objective for building a requirements modelA) define set of software requirements that can be validatedB) describe customer requirementsC)develop an abbreviated solution for the problemD) establish basis for software designSectionObject-oriented domain analysis is concerned with the identification and specification of reusable capabilities within an application domain.A)TrueB) FalseSectionIn structured analysis models focus on the structure of the classes defined for a system along with their interactions.A) TrueB)FalseSection5Creation and refinement of use cases if an important part of scenario-based modeling.A)TrueB) FalseSectionIt is important to consider alternative actor interactions when creating a preliminary use case.A) TrueB)FalseSectionBrainstorming is one technique that may be used to derive a complete set of use case exceptions.A)TrueB) FalseSectionIn many cases there is no need to create a graphical representation of a usage scenario.A)TrueB) FalseSectionUML activity diagrams are useful in representing which analysis model elementsA) Behavioral elementsB) Class-based elementsC) Flow-based elementsD)Scenario-based elementsSectionOne or more attributes of a data object must be defined as a key to allow the location of an instance of the data object.A)TrueB) FalseSectionThe entity relationship diagramA)depicts relationships between data objectsB) depicts functions that transform the data flowC) indicates how data are transformed by the systemD) indicates system reactions to external eventsSectionWhich of the following should be considered as candidate objects in a problem spaceA) eventsB) peopleC) structuresD)all of the aboveSectionAttributes are chosen for an object by examining the problem statement and identifying the entities that appear to be related.A) TrueB)FalseSectionWhich of the following is not one of the broad categories used to classify operationsA) computationB) data manipulationC) event monitorsD)transformersSectionWhich of the following items does not appear on a CRC cardA) class collaboratorsB) class nameC)class reliabilityD) class responsibilitiesSectionClass responsibilities are defined byA) its attributes onlyB) its collaboratorsC) its operations onlyD)both its attributes and operationsSectionAn analysis package involves the categorization of analysis model elements into useful groupings.A)TrueB) FalseChapter 71The data flow diagramA) depicts relationships between data objectsB) depicts functions that transform the data flowC) indicates how data are transformed by the systemD) indicates system reactions to external eventsE)both b and cSectionControl flow diagrams areA)needed to model event driven systems.B) required for all systems.C) used in place of data flow diagrams.D) used to represent system behavior.SectionThe control specification represents the system behavior using UML sequence and state diagrams.A)TrueB) FalseSectionThe data flow diagram must be augmented by min-spec that can serve as a guide the design of the software component that will implement the process.A)TrueB) FalseSectionFor purposes of behavior modeling an event occurs wheneverA) a state and process exchange information.B)the system an actor exchange information.C) two actors exchange information.D) two objects exchange information.SectionFor purposes of behavior modeling a state is anyA) consumer or producer of data.B) data object hierarchy.C)observable mode of behavior.D) well defined process.SectionThe state transition diagramA) depicts relationships between data objectsB) depicts functions that transform the data flowC) indicates how data are transformed by the systemD)indicates system reactions to external eventsSectionThe UML sequence diagram show the order in which system events are processed.A) TrueB)FalseSection9Analysis patterns are discovered, they are not explicitly created.A)TrueB) FalseSection10It is not possible to justify the time required for WebApp requirements analysis.A) TrueB)FalseSectionWhich is not one of the analysis activities that is used to create a complete analysis modelA) Configuration analysisB) Content analysisC) Functional analysisD)Market analysisSectionContent objects are extracted from use cases by examining the scenario description for direct or indirect content references.A)TrueB) FalseSectionWhat are the elements of a WebApp interaction modelA) activity diagrams, sequence diagrams, state diagrams, interface prototypeB) activity diagrams, collaboration diagrams, sequence diagrams, state diagramsC)use-cases, sequence diagrams, state diagrams, interface prototypeD) use-cases, sequence diagrams, state diagrams, sequence diagramsSectionUML activity diagrams can be used to represent the user observable functionality delivered by the WebApp as well as the operations contained in each analysis class.A)TrueB) FalseSectionConfiguration analysis focuses on the architecture of the user's web browsing environment.A) TrueB)FalseChapter 81Which of the following are areas of concern in the design modelA) architectureB) dataC) interfacesD) project scopeE)a, b, and cSection2The importance of software design can be summarized in a single wordA) accuracyB) complexityC) efficiencyD)qualitySectionWhich of these are characteristics of a good designA) exhibits strong coupling between its modulesB) implements all requirements in the analysis modelC) includes test cases for all componentsD) provides a complete picture of the softwareE)both b and dSectionWhich of the following is not a characteristic common to all design methodsA)configuration managementB) functional component representationC) quality assessment guidelinesD) refinement heuristicsSectionWhat types of abstraction are used in software designA) controlB) dataC) environmentalD) proceduralE)a, b, and dSectionWhich of the following can be used to represent the architectural design of a piece of softwareA) Dynamic modelsB) Functional modelsC) Structural modelsD)All of the aboveSectionDesign patterns are not applicable to the design of object-oriented softwareA) TrueB)FalseSectionSince modularity is an important design goal it is not possible to have too many modules in a proposed design.A) TrueB)FalseSectionInformation hiding makes program maintenance easier by hiding data and procedure from unaffected parts of the program.A)TrueB) FalseSectionCohesion is a qualitative indication of the degree to which a moduleA) can be written more compactly.B)focuses on just one thing.C) is able to complete its function in a timely manner.D) is connected to other modules and the outside world.SectionCoupling is a qualitative indication of the degree to which a moduleA) can be written more compactly.B) focuses on just one thing.C) is able to complete its function in a timely manner.D)is connected to other modules and the outside world.SectionWhen using structured design methodologies the process of stepwise refinement is unnecessary.A) TrueB)FalseSectionSoftware designs are refactored to allow the creation of software that is easier to integrate, easier to test, and easier to maintain.A)TrueB) FalseSectionWhich of the following is not one of the five design class typesA) Business domain classesB)Entity classesC) Process classesD) User interface classesSectionWhich design model elements are used to depict a model of information represented from the user's viewA) Architectural design elementsB) Component-level design elementsC)Data design elementsD) Interface design elementsSectionWhich design is equivalent to the floor plan of a houseA)Architectural designB) Component-level designC) Data designD) Interface designSectionWhich design model is equivalent to the detailed drawings of the access points and external utilities for a houseA) Architectural designB) Component-level designC) Data designD)Interface designSectionWhich design model is equivalent to a set of detailed drawings for each room in a houseA) Architectural designB)Component-level designC) Data designD) Interface designSectionThe deployment design elements specify the build order for the software components.A) TrueB)FalseChapter 91The best representation of system architecture is an operational software prototype.A) TrueB)FalseSectionThe architectural representations can be an enabler for communication among project stakeholders.A)TrueB) FalseSectionAn architectural description is often documented using an architecture template.A) TrueB)FalseSection4An architectural genre will often dictate the architectural approach that may used for the structure to be built.A)TrueB) FalseSection5An architectural style encompasses which of the following elementsA) constraintsB) set of componentsC) semantic modelsD) syntactic modelsE)a, b, and cSectionTo determine the architectural style or combination of styles that best fits the proposed system, requirements engineering is used to uncoverA) algorithmic complexityB)characteristics and constraintsC) control and dataD) design patternsSectionBefore an architectural pattern can be chosen for use in a specific system it must have a code implementation to facilitate its reuse.A) TrueB)FalseSectionThe criteria used to assess the quality of an architectural design should be based on systemA) accessibilityB) controlC) dataD) implementationE)both b and cSectionDuring process of modeling the system in context, systems that interact with the target system are represented asA) Peer-level systemsB) Subordinate systemsC) Superordinate systemsD) Working systemsE)a, b, and cSectionOnce selected, archetypes always need to be refined further as architectural design proceeds.A)TrueB) FalseSectionWhich of the following is not an example of infrastructure components that may need to be integrated into the software architectureA) Communications componentsB) Database componentsC)Interface componentsD) Memory management componentsSectionIn the architecture trade-off analysis method the architectural style should be described using theA) data flow viewB) module viewC) process viewD) user viewE)a, b, and cSectionQuantitative methods for assessing the quality of proposed architectural designs are readily available.A) TrueB)FalseSectionA useful technique for evaluating the overall complexity of a proposed architecture is to look at the componentA) cohesionB) flow dependenciesC) sharing dependenciesD) sizeE)both b and cSection15When the overall flow in a segment of a data flow diagram is largely sequential and follows straight-line paths _________ is present.A) low couplingB) good modularityC) transaction flowD)transform flowSectionWhen a single item that triggers other data flow along one of many paths ________ characterizes the information flow in a segment of a data flow diagram is present.A) high couplingB) poor modularityC)transaction flowD) transform flowChapter 101In the most general sense a component is a modular building block for computer software.A)TrueB) FalseSectionIn the context of object-oriented software engineering a component containsA) attributes and operationsB) instances of each classC) roles for each actor (device or user)D)set of collaborating classesSectionIn traditional software engineering modules must serve in which of the following rolesA) Control componentB) Infrastructure componentC) Problem domain componentD)All of the aboveSectionSoftware engineers always need to cerate components from scratch in order to meet customer expectations fully.A) TrueB)FalseSectionWhich of the following is not one of the four principles used to guide component-level designA) Dependency Inversion PrincipleB) Interface Segregation PrincipleC) Open-Closed PrincipleD)Parsimonious Complexity PrincipleSectionThe use of stereotypes can help identify the nature of components at the detailed design level.A)TrueB) FalseSectionClasses and components that exhibit functional, layer, or communicational cohesion are relatively easy to implement, test, and maintain.A)TrueB) FalseSectionSoftware coupling is a sign of poor architectural design and can always be avoided in every system.A) TrueB)FalseSection9In component design elaboration requires which of the following elements to be describe in detailA) AlgorithmsB) Attributes。

(完整版)川大软院计网选择题答案Chapter1(含答案)

1.1 In the following options, which does not define in protocol? ( D )A the format of messages exchanged between two or more communicatingentitiesB the order of messages exchanged between two or more communicating entitiesC the actions taken on the transmission of a message or other eventD the transmission signals are digital signals or analog signals1.2 In the following options, which is defined in protocol? ( A )A the actions taken on the transmission and/or receipt of a message or other eventB the objects exchanged between communicating entitiesC the content in the exchanged messagesD the location of the hosts1.3 An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes (C ).A flow controlB congestion-controlC reliable data transferD connection-oriented service1.4 The Internet’s connection-oriented service has a name, it is ( A ).A TCPB UDPC TCP/IPD IP1.5 The Internet’s connectionless service is called ( B ).A TCPB UDPC TCP/IPD IP1.6 Which of the following nodes belongs to the network core?CA. a Web ServerB. a Host with Win2003 ServerC. a Router with NAT serviceD. a Supernode on Skype Network1.7 In the Internet, the equivalent concept to end systems is ( )A.A hostsB serversC clientsD routers1.8 In the Internet, end systems are connected together by ( C ).A copper wireB coaxial cableC communication linksD fiber optics1.9 End systems access to the Internet through its (C ).A modemsB protocolsC ISPD sockets1.10 In the following options, which belongs to the network core? ( B )A end systemsB routersC clientsD servers1.11 End systems, packet switches, and other pieces of the Internet, run ( D ) that control the sending and receiving of information within the Internet.A programsB processesC applicationsD protocols1.12 The internet allows ( D ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications1.13 The protocols of various layers are called ( A ).A the protocol stackB TCP/IPC ISPD network protocol1.14 In the OSI reference model, the upper layers of the OSI model are, in correct orderDA Session, application, presentationB Session, presentation, applicationC Session, application, presentation, physicalD Application, presentation, session1.15 The lower layers of the OSI model are, in correct orderDA physical, system, network, logicalB physical, logical, network, systemC physical, transport, network, data linkD physical, data link, network, transport1.16 The Internet Protocol (IP) generally corresponds to which OSI layer?AA Network (layer three)B Transport (layer four)C Data link (layer two)D Session (layer five)1.17 What layer of the OSI model is designed to perform error detection functions?BA PhysicalB Data linkC NetworkD transport1.18 Which of the following protocol layers is not explicitly part of the Internet Protocol Stack? _____B____A. application layerB. session layerC. data link layerD. transport layer1.19 The 5-PDU is called__A_A. messageB. segmentC. datagramD. frame1.20 The Internet’s network layer is responsible for moving network-layer packets known as B( ) from one host to another.A frameB datagramC segmentD message1.21 Transport-layer packets are called:BA. messageB. segmentC. datagramD. frame1.22 The units of data exchanged by a link-layer protocol are called ( A).A FramesB SegmentsC DatagramsD bit streams1.23 There are two fundamental approaches to building a network core, ( B ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching1.24 Datagram networks and virtual-circuit networks differ in that ( C ).A datagram networks are circuit-switched networks, and virtual-circuit networksare packet-switched networks.B datagram networks are packet-switched networks, and virtual-circuit networksare circuit-switched networks.C datagram networks use destination addresses and virtual-circuit networks useVC. numbers to forward packets toward their destination.D datagram networks use VC. numbers and virtual-circuit networks usedestination addresses to forward packets toward their destination.1.25 (A ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connectionD TDM1.26 In ( C ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.A packet-switchedB data-switchedC circuit-switchedD message-switched1.27 In ( A ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link.A packet-switchedB data-switchedC circuit-switchedD message-switched1.28 In a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( A) of the link’s bandwidth for the duration of the connection.A a fraction 1/nB allC 1/2D n times1.29 For (C ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot.A CDMAB packet-switched networkC TDMD FDM1.30 The network that forwards packets according to host destination addresses is called ( D) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram1.31 The network that forwards packets according to virtual-circuit numbers is called ( C ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagram1.32 The time required to propagate from the beginning of the link to the next router is ( C).A queuing delayB processing delayC propagation delayD transmission delay1.33 Processing delay does not include the time to (B ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet1.34 In the following four descriptions, which one is correct? ( C)A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensity decreases.C If the traffic intensity is close to zero, the average queuing delay will be closeto zero.D If the traffic intensity is close to one, the average queuing delay will be closeto one.1.35 Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( B ),A LR／aB La／RC Ra／LD LR／a1.36 Suppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 and R2, respectively. Assuming that the switch uses store-and-forward packet switching, what is the total end-to-end delay to send a packet of length L? (Ignore queuing delay, propagation delay, and processing delay.) ( A )A L/R1＋L/R2B L/R1C L/R2D none of the above1.37 We are sending a 30 Mbit MP3 file from a source host to a destination host. Suppose there is only one link between source and destination and the link has a transmission rate of 10 Mbps. Assume that the propagation speed is 2 * 108 meters/sec, and the distance between source and destination is 10,000 km. Also suppose that message switching is used, with the message consisting of the entire MP3 file. How many bits will the source have transmitted when the first bit arrives at the destination?CA. 1 bitB. 30,000,000 bitsC. 500,000 bitsD. none of the above1.38 In the following entries, which is not a kind of access network?(D )A residential accessB company accessC wireless accessD local access1.39 The following technologies may be used for residential access, exceptDA. HFCB. DSLC. Dial-up modemD. FDDI1.40 Which kind of media is not a guided media? ( D)A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel。

(完整版)川大软院计网选择题答案Chapter3(含答案)

CHAPTER 3: TRANSPORT LAYER1. A transport-layer protocol provides for logical communication between ___C_.A.RoutersB.HostsC.Application processesD.End systems2.Transport-layer protocols run in __D__.A.ServersB.ClientsC.RoutersD.End systems3.In transport layer, the send side breaks application messages into ___B_, passes tonetwork layer.A.FramesB.SegmentsC.Data-gramsD.bit streams4.The receive side of transport layer reassembles segments into messages, passes to__A__layer.A.ApplicationworkingC.PhysicalD.MAC5.Services provided by transport layer include __C__.A.HTTP and FTPB.TCP and IPC.TCP and UDPD.SMTP6.Which of the following services is not provided by TCP?DA.In-order data transfersB.Reliable data transfers and flow controlsC.Congestion controlsD.Delay guarantees and bandwidth guarantees7.These two minimal transport-layer services----___A_ and ____----are the only twoservices that UDP providesA.process-to-process data delivery, error checkingB.congestion control, reliable data transferC.flow control, congestion controlD.In-order data transfer, error checking8.UDP offers which of the following benefits relative to TCP?CA.UDP guarantees that Individual packets of a transmission will arrive “infeature that prevents networkB.UDP supports a self-regulating “throttle”　saturationC.UDP consumes fewer computer resources by not maintaining connection stateD.None of the above9.Which of the following applications normally uses UDP services?BA.SMTPB.Streaming multimediaC.FTPD.HTTP10.The job of gathering data chunks, encapsulating each data chunk with headerinformation to create segments and passing the segments to the network is called__A__.A.multiplexingB.de-multiplexingC.forwardingD.routing11.This job of delivering the data in a transport-layer segment to the correct socket iscalled _B___.A.multiplexingB.de-multiplexingC.forwardingD.routingB_ to ____.12.Port number’s scope is ___A.0, 1023B.0, 65535C.0, 127D.0,25513.The port numbers ranging from __C__to ____ are called well-known port numberand are restricted.A.0, 127B.0, 65535C.0, 1023D.0,25514.The UDP header has only four fields, they are__A__.A.Source port number, destination port number, length and checksumB.Source port number, destination port number, source IP and destination IPC.source IP, destination IP, source MAC address and destination MAC addressD.source IP, destination IP, sequence number and ACK sequence number15.The field of Length in UDP segment specifies the length of ___B_.A.the UDP segment, not including the headerB.the UDP segment, including the headerC.the UDP segment’s headerD.the Length field16.Which of the following about TCP connection is not correct?AA.It is a broadcast connectionB.It is a point-to-point connectionC.It is a pipelined connectionD.It is a full duplex connection17.In the following four descriptions about MSS and MTU, which one is not correct?CA.The MSS is typically set by MTUB.The MSS is the maximum size of the TCP segment including headersC.The MSS is the maximum amount of application-layer data in the segmentD.The MTU means the largest link-layer frame18.__A__ is the byte stream number of first byte in the segment.A.Sequence numberB.ACK numberC.ChecksumD.port number19.__B__ is the byte sequence numbers of next byte expected from other side.A.Sequence numberB.ACK numberC.ChecksumD.port number20.In the following four options, which one is correct?DA.Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Thenthe current value of TimeoutInterval will necessarily be≤1 secB.The timeout should be less than the connection’s RTTC.Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Thenthe current value of TimeoutInterval will necessarily be≥1 secD.The variations in the SampleRTT are smoothed out in the computation of theEstimatedRTT21.There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Theirchecksum is__A__.A.0100010001000011B.1011101110111100C.1111111111111111D.100000000000000022.Suppose host A sends host B one TCP segment with sequence number 418,acknowledgement number 571, and 4 bytes of data. Then the sequence number in the acknowledgement to this segment is _____C____A.422B. 418C. 571D. 57523.Because TCP only acknowledges bytes up to the first missing byte in the stream,TCP is said to provide__D__.A.positive ACKsB.Selective acknowledgementsC. 3 duplicate ACKsD.Cumulative acknowledgements24.If we define N to be the window size, base to be the sequence number of the oldestunacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval [nextseqnum,base+N-1] corresponds to packet that __A__.A.can be sent immediatelyB.have already been transmitted and acknowledgedC.cannot be usedD.have been sent but not yet acknowledged25.Which of the following is not a pipelining protocol.AA.Rdt1.0B.Go-Back-NC.Selective repeatD.TCP26.What is the main difference between stop-and-wait and pipelined reliable datatransfer protocol?BA.The pipelined protocol uses the NAK packets, whereas in the stop-and-waitprotocol senders always wait for ACK packets.B.With the pipelined protocol, the sender can send several packets in row,whereas in the stop-and-wait protocol the sender cannot send the packets inrow.C.With the pipelined protocol, the receiver must send one ACK for severalpackets (cumulative ACK), whereas in the stop-and-wait protocol the receivercan not send the cumulative ACK.D.The pipelined protocol uses timeouts, whereas the stop-and-wait protocol doesnot use the timeout.27.Fast retransmit means in the case that __D__ duplicate ACK-s are received, theTCP sender resend segment before timer expires.A.6B.5C.4D.328.__B__ is a speeding-matching service---matching the rate which the sender issending against the rate at which the receiving application is reading.A.congestion controlB.flow controlC.sliding-window controlD.variable control29.TCP provides flow control by having the sender maintain a variable called the__D__.A.bufferB.Congestion windowC.Sliding windowD.Receive window30.Provided RcvBuffer = 20, LastByteRcvd = 20, LastByteRead = 15, thenRcvWindow=__B__.A.14B.15C.16D.1031.In the following four descriptions about TCP connection management, which oneis not correct?DA.Either of the two processes p articipating in a TCP connection can end theconnectionB.If the FIN bit is set to 1, it means that it wants to close the connectionC.In the first two step of the three-way handshake, the client and server randomlychoose an initial sequence numberD.In the three segments of the three-way handshake, the SYN bit must be set to132.How does TCP sender perceive congestion?DA.Through a timeout eventB.Through a receiving duplicate ACK-s eventC.Both A and BD.Either A or B33.There are two states in TCP congestion control, which are _C___.A.safe start and congestion abandonB.safe start and congestion avoidanceC.slow start and congestion avoidanceD.slow start and congestion abandon34.In TCP, the timeout interval is a function of:AA.estimated RTT at the senderB. MSS and the overhead of a segmentB.the size of buffer at the receiver D. the size of sending window35.In a TCP connection, there is timeout event when the value of threshold is 32 andthe size of congestion window is 16. According to the TCP congestion control policy, the new value of threshold and the new size of congestion window should be ______C__, respectively.A.16, 8B. 24, 8C. 8, 1D. 16, 1。

四川大学软件工程考试试题05-06A

四川大学期末考试试题A（闭卷）
（2005 ——2006 学年第一学期）
课程号：课序号：课程名称：软件工程任课教师：成绩：适用专业年级：学生人数：印题份数：学号：姓名：
注：1试题字迹务必清晰，书写工整。

本题 3 页，本页为第 1 页
2 题间不留空，一般应题卷分开教务处试题编号：
3务必用A4纸打印
本题 3 页，本页为第 2 页
教务处试题编号：
学号：姓名
V(G)。

为了完成基本路径测试，求它的一组独立的路径。

要求用户输入处理报表的日期，日期限制在2003
只能对该段期间内的报表进行处理，如日期不在此范围内，则显示输入错误信息。

位数字字符组成，前四位代表年，后两位代表月。

现要求用黑盒测试法中的边界值法写出测试
本题 3 页，本页为第 3 页
教务处试题编号：。

四川大学计算机软件技术基础复习题2与答案

《计算机软件技术基础》复习题2参考答案1. 从工作的角度看操作系统,可以分为单用户系统、批处理系统、 B 和实时系统。

A. 单机操作系统B. 分时操作系统C. 面向过程的操作系统D. 网络操作系统2. 在下列系统中， B 是实时系统。

A. 计算机激光照排系统B. 航空定票系统C. 办公自动化系统D. 计算机辅助设计系统3. 操作系统是一种 B 。

A. 应用软件B. 系统软件C. 通用软件D. 工具软件4. 引入多道程序的目的在于 A 。

A. 充分利用CPU，减少CPU等待时间B. 提高实时响应速度C. 有利于代码共享，减少主、辅存信息交换量D. 充分利用存储器5. 已经获得除Ｃ以外的所有运行所需资源的进程处于就绪状态。

A. 存储器B. 打印机C. CPUD. 内存空间6. 进程调度的关键问题：一是选择合理的 B ，二是恰当地进行代码转换。

A. 时间片间隔B. 调度算法C. CPU速度D. 内存空间7. 采用轮转法调度是为了 A 。

A. 多个终端都能得到系统的及时响应B. 先来先服务C. 优先级较高的进程得到及时调度D. 需CPU最短的进程优先8. 在一段时间内只允许一个进程访问的资源，称为 C 。

A. 共享资源B. 临界区C. 临界资源D. 共享区9. 并发性是指若干事件在 B 发生。

A. 同一时刻B. 同一时间间隔C. 不同时刻D. 不同时间间隔10.在单一处理器上，将执行时间有重叠的几个程序称为 C 。

A. 顺序程序B. 多道程序C. 并发程序D. 并行程序11.程序运行时，独占系统资源，只有程序本身能改变系统资源状态，这是指 B 。

A. 程序顺序执行的再现性B. 程序顺序执行的封闭性C. 并发程序失去封闭性D. 并发程序失去再现性12.引入多道程序技术后，处理器的利用率Ｃ。

A. 降低了B. 有所改善C. 大大提高D. 没有变化，只是程序的执行方便了13.在单一处理器上执行程序，多道程序的执行是在 B 进行的。

2022年四川大学软件工程专业《操作系统》科目期末试卷A(有答案)

2022年四川大学软件工程专业《操作系统》科目期末试卷A（有答案）一、选择题1、假设4个作业到达系统的时刻和运行时间见表。

系统在t=2时开始作业调度。

若分别采用先来先服务和短作业优先调度算法，则选中的作业分别是（）。

A.J2、J3B.J1、J4C.J2、J4D.J1、J32、下列关于操作系统的论述中，正确的是（）。

A.对于批处理作业，必须提供相应的作业控制信息B.对于分时系统，不一定全部提供人机交互功能C.从响应角度看，分时系统与实时系统的要求相似D.在采用分时操作系统的计算机系统中，用户可以独占计算机操作系统中的文件系统3、通常用户进程被建立后（）A.使一直存在于系统中，直到被操作人员撤销B.随着作业运行正常或不正常结束而撤销C.随着时间片轮转而撤销与建立D.随着进程的阻塞或唤醒而撤销与建立4、进程从运行态到阻塞态可能是（）A.运行进程执行P操作B.进程调度程序的调度C.运行进程的时间片用完D.运行进程执行了V操作5、进程调度算法中，可以设计成可抢占式的算法有（）。

A.先来先服务调度算法B.最高响应比优先调度算法C.最短作业优先调度算法D.时间片轮转调度算法6、某进程访问页面的序列如下所示。

若工作集的窗口大小为6，则在t时刻的工作集为（）。

A.（6，0，3，2）B. （2，3，0，4）C.（0，4，3，2，9）D.（4，5，6，0，3，2）7、系统将数据从磁盘读到内存的过程包括以下操作：① DMA控制器发出中断请求②初始化DMA控制器并启动磁盘③从磁盘传输一块数据到内存缓冲区④执行“DMA结束”中断服务程序正确的执行顺序是（）：A.③①②④B.②③①④C.②①③④D.①②③④8、在系统内存中设置磁盘缓冲区的主要11的是（）。

A.减少磁盘1/0次数，B.减少平均寻道时间C.提高磁盘数据可靠性D.实现设备无关性9、下面关于文件的叙述中，错误的是（）。

I.打开文件的主要操作是把指定文件复制到内存指定的区域II.对一个文件的访问，常由用户访问权限和用户优先级共同限制III.文件系统采用树形片录结构后，对于不同用户的文件，其文件名应该不同IV.为防止系统故障造成系统内文件受损，常采用存取控制矩阵方法保护文件A.仅IB. 仅I、IIIC.仅I、III、IVD.I、II、III，IV10、产生内存抖动的主要原因是（）A.内存空间太小B.CPU运行速度太慢C.CPU调度算法不合理D.页面置换算法不合理11、假定有个请求分页存储管理系统，测得系统各相关设备的利用率为：CPU为10%，磁盘交换区为99.7%：其他1/O设备为5%。

川大软院计网选择题答案Chapter5(含答案)

1. A ( D) protocol is used to move a packet over an individual 独立link.A. application-layerB. transport-layerC. network-layerD. link-layer2. Which of the following services can not offered by a link-layer protocol? ( )A. congestion controlB. Link AccessC. Error controlD. FramingHint：framing, link access，reliable delivery，flow control，error detection，error correction，half-duplex and full-duplex3. ( B ) protocol serves to 为……服务coordinate 协调the frame transmissionsof the many nodes when multiple nodes share a single broadcast link.A. ARPB. MACC. ICMPD. DNS4. Consider CRC error checking approach, the four bit generator G is 1011, andsuppose that the data D is 10101010, then the value of R is ( A).A. 010B. 100C. 011D. 1105. In the following four descriptions说明about random access protocol, whichone is not correct? ( A )A. In slotted ALOHA, nodes can transmit at random time.B. CSMA/CD cannot be implemented on a wireless channel.C. The maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.D. In CSMA/CD, one node listens to the channel before transmitting.6. In the following descriptions about MAC address, which one is not correct?( D )A. The MAC address is the address of one node’s adapter.B. No two adapters have the same MAC address.C. The MAC address doesn’t change no matter where the adapter goes.D. MAC address has a hierarchical structure分层结构.MAC：flat structureIP：hierarchical structure7. The ARP protocol can translate ( ) into ( ). ( C )A. host name, IP addressB. host name, MAC addressC. IP address, MAC addressD. broadcast address, IP address8. The value of Preamble field in Ethernet frame structure is ( C)A. 10101010 10101010……10101010 11111111B. 10101011 10101011……10101011 10101011C. 10101010 10101010……10101010 10101011D. 10101010 10101010……10101010 101010109. In CSMA/CD, the adapter waits some time and then returns to sensing thechannel. In the following four times, which one is impossible? ( D)A. 0 bit timesB. 512 bit timesC. 1024 bit timesD. 1028 bit times10. The principal components of PPP include but not( D ).A. framingB. physical-control protocolC. link-layer protocolD. network-layer protocol11. Consider the data D is 01110010001, if use even parity checking approach, theparity bit is( ① ), if use odd parity checking approach, the parity bit is( ② ). ( D )A. ① 0 ② 1B. ① 0 ② 0C. ① 1 ② 1D. ① 1 ② 012. In the following four descriptions, which one is not correct? (B )A. Switches can interconnect different LAN technologies.B. Hubs can interconnect different LAN technologies.C. There is no limit to how large a LAN can be when switches are used tointerconnect LAN segments.D. There is restriction on the maximum allowable number of nodes in a collisiondomain when hubs are used to interconnect LAN segments.13. Which of the following devices is not a plug and play device? ( B )A. hubB. routerC. switchD. repeater14. Which device has the same collision domain? ( A )A. HubB. SwitchC. RouteD. Bridge15. In data link-layer, which protocol is used to share bandwidth? ( D)A. SMTPB. ICMPC. ARPD. CSMA/CD16. When two or more nodes on the LAN segments transmit at the same time, therewill be a collision and all of the transmitting nodes well enter exponential back-off, that is all of the LAN segments belong to the same( A ).A. collision domainB. switchC. bridgeD. hub17. In the following four descriptions about PPP, which one is not correct? ( D )A. PPP is required to detect and correct errors.B. PPP is not required to deliver frames to the link receiver in the same order inwhich they were sent by the link sender.C. PPP need only operate over links that have a single sender and a singlereceiver.D. PPP is not required to provide flow control.18. For ( A ) links that have a single sender at one end of the link and a singlereceiver at the other end of the link.A. point-to-pointB. broadcastC. multicastD. all of the above19. With(B )transmission, the nodes at both ends of a link may transmit packets atthe same time.A. half-duplexB. full-duplexC. simplex(单工)D.synchronous20. Which of the following is wrong? ( A )A. ARP table is configured by a system administratorB. ARP table is built automaticallyC. ARP table is dynamicD. ARP table maps IP addresses to MAC addresses21. In LAN, if UTP is used, the common connector is (C ).A. AUIB. BNCC. RJ-45D. NNI22. Which of the following four descriptions about MAC addresses is wrong? ( C )A. a MAC address is burned into the adapter’s ROMB. No two adapters have the same addressC. An adapter’s MAC address is dynamicD. A MAC address is a link-layer address23. In the CSMA/CD protocol, what condition on the transmission delay andthe propagation delay has to be satisfied to guarantee that a node always detects a collision? BA. B.C. D.。

(完整版)川大软院计网选择题答案Chapter3(含答案)

CHAPTER 3: TRANSPORT LAYER1. A transport-layer protocol provides for logical communication between ___C_.A.RoutersB.HostsC.Application processesD.End systems2.Transport-layer protocols run in __D__.A.ServersB.ClientsC.RoutersD.End systems3.In transport layer, the send side breaks application messages into ___B_, passes tonetwork layer.A.FramesB.SegmentsC.Data-gramsD.bit streams4.The receive side of transport layer reassembles segments into messages, passes to__A__layer.A.ApplicationworkingC.PhysicalD.MAC5.Services provided by transport layer include __C__.A.HTTP and FTPB.TCP and IPC.TCP and UDPD.SMTP6.Which of the following services is not provided by TCP?DA.In-order data transfersB.Reliable data transfers and flow controlsC.Congestion controlsD.Delay guarantees and bandwidth guarantees7.These two minimal transport-layer services----___A_ and ____----are the only twoservices that UDP providesA.process-to-process data delivery, error checkingB.congestion control, reliable data transferC.flow control, congestion controlD.In-order data transfer, error checking8.UDP offers which of the following benefits relative to TCP?CA.UDP guarantees that Individual packets of a transmission will arrive “in order”B.UDP supports a self-regulating “throttle” feature that prevents networksaturationC.UDP consumes fewer computer resources by not maintaining connection stateD.None of the above9.Which of the following applications normally uses UDP services?BA.SMTPB.Streaming multimediaC.FTPD.HTTP10.The job of gathering data chunks, encapsulating each data chunk with headerinformation to create segments and passing the segments to the network is called __A__.A.multiplexingB.de-multiplexingC.forwardingD.routing11.This job of delivering the data in a transport-layer segment to the correct socket iscalled _B___.A.multiplexingB.de-multiplexingC.forwardingD.routing12.Port number’s scope is ___B_ to ____.A.0, 1023B.0, 65535C.0, 127D.0,25513.The port numbers ranging from __C__to ____ are called well-known port numberand are restricted.A.0, 127B.0, 65535C.0, 1023D.0,25514.The UDP header has only four fields, they are__A__.A.Source port number, destination port number, length and checksumB.Source port number, destination port number, source IP and destination IPC.source IP, destination IP, source MAC address and destination MAC addressD.source IP, destination IP, sequence number and ACK sequence number15.The field of Length in UDP segment specifies the length of ___B_.A.the UDP segment, not including the headerB.the UDP segment, including the headerC.the UDP segment’s headerD.the Length field16.Which of the following about TCP connection is not correct?AA.It is a broadcast connectionB.It is a point-to-point connectionC.It is a pipelined connectionD.It is a full duplex connection17.In the following four descriptions about MSS and MTU, which one is not correct?CA.The MSS is typically set by MTUB.The MSS is the maximum size of the TCP segment including headersC.The MSS is the maximum amount of application-layer data in the segmentD.The MTU means the largest link-layer frame18.__A__ is the byte stream number of first byte in the segment.A.Sequence numberB.ACK numberC.ChecksumD.port number19.__B__ is the byte sequence numbers of next byte expected from other side.A.Sequence numberB.ACK numberC.ChecksumD.port number20.In the following four options, which one is correct?DA.Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Thenthe current value of TimeoutInterval will necessarily be≤1 secB.The timeout should be less than the connection’s RTTC.Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Thenthe current value of TimeoutInterval will necessarily be≥1 secD.The variations in the SampleRTT are smoothed out in the computation of theEstimatedRTT21.There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Theirchecksum is__A__.A.0100010001000011B.1011101110111100C.1111111111111111D.100000000000000022.Suppose host A sends host B one TCP segment with sequence number 418,acknowledgement number 571, and 4 bytes of data. Then the sequence number in the acknowledgement to this segment is _____C____A.422B. 418C. 571D. 57523.Because TCP only acknowledges bytes up to the first missing byte in the stream,TCP is said to provide__D__.A.positive ACKsB.Selective acknowledgementsC. 3 duplicate ACKsD.Cumulative acknowledgements24.If we define N to be the window size, base to be the sequence number of the oldestunacknowledged packet, and next-seq-num to be the smallest unused sequence number, then the interval [nextseqnum,base+N-1] corresponds to packet that __A__.A.can be sent immediatelyB.have already been transmitted and acknowledgedC.cannot be usedD.have been sent but not yet acknowledged25.Which of the following is not a pipelining protocol.AA.Rdt1.0B.Go-Back-NC.Selective repeatD.TCP26.What is the main difference between stop-and-wait and pipelined reliable datatransfer protocol?BA.The pipelined protocol uses the NAK packets, whereas in the stop-and-waitprotocol senders always wait for ACK packets.B.With the pipelined protocol, the sender can send several packets in row,whereas in the stop-and-wait protocol the sender cannot send the packets inrow.C.With the pipelined protocol, the receiver must send one ACK for severalpackets (cumulative ACK), whereas in the stop-and-wait protocol the receivercan not send the cumulative ACK.D.The pipelined protocol uses timeouts, whereas the stop-and-wait protocol doesnot use the timeout.27.Fast retransmit means in the case that __D__ duplicate ACK-s are received, theTCP sender resend segment before timer expires.A.6B.5C.4D.328.__B__ is a speeding-matching service---matching the rate which the sender issending against the rate at which the receiving application is reading.A.congestion controlB.flow controlC.sliding-window controlD.variable control29.TCP provides flow control by having the sender maintain a variable called the__D__.A.bufferB.Congestion windowC.Sliding windowD.Receive window30.Provided RcvBuffer = 20, LastByteRcvd = 20, LastByteRead = 15, thenRcvWindow=__B__.A.14B.15C.16D.1031.In the following four descriptions about TCP connection management, which oneis not correct?DA.Either of the two processes participating in a TCP connection can end theconnectionB.If the FIN bit is set to 1, it means that it wants to close the connectionC.In the first two step of the three-way handshake, the client and server randomlychoose an initial sequence numberD.In the three segments of the three-way handshake, the SYN bit must be set to132.How does TCP sender perceive congestion?DA.Through a timeout eventB.Through a receiving duplicate ACK-s eventC.Both A and BD.Either A or B33.There are two states in TCP congestion control, which are _C___.A.safe start and congestion abandonB.safe start and congestion avoidanceC.slow start and congestion avoidanceD.slow start and congestion abandon34.In TCP, the timeout interval is a function of:AA.estimated RTT at the senderB. MSS and the overhead of a segmentB.the size of buffer at the receiver D. the size of sending window35.In a TCP connection, there is timeout event when the value of threshold is 32 andthe size of congestion window is 16. According to the TCP congestion control policy, the new value of threshold and the new size of congestion window should be ______C__, respectively.A.16, 8B. 24, 8C. 8, 1D. 16, 1。

川大软院计网选择题答案Chapter5(含答案)

1. A ( D) protocol is used to move a packet over an individual 独立link.A. application-layerB. transport-layerC. network-layerD. link-layer2. Which of the following services can not offered by a link-layer protocol? ( )A. congestion controlB. Link AccessC. Error controlD. FramingHint：framing, link access，reliable delivery，flow control，error detection，error correction，half-duplex and full-duplex3. ( B ) protocol serves to 为……服务coordinate 协调the frame transmissionsof the many nodes when multiple nodes share a single broadcast link.A. ARPB. MACC. ICMPD. DNS4. Consider CRC error checking approach, the four bit generator G is 1011, andsuppose that the data D is 10101010, then the value of R is ( A).A. 010B. 100C. 011D. 1105. In the following four descriptions说明about random access protocol, whichone is not correct? ( A )A. In slotted ALOHA, nodes can transmit at random time.B. CSMA/CD cannot be implemented on a wireless channel.C. The maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.D. In CSMA/CD, one node listens to the channel before transmitting.6. In the following descriptions about MAC address, which one is not correct? ( D )A. The MAC address is the address of one node’s ada pter.B. No two adapters have the same MAC address.C. The MAC address doesn’t change no matter where the adapter goes.D. MAC address has a hierarchical structure分层结构.MAC：flat structureIP：hierarchical structure7. The ARP protocol can translate ( ) into ( ). ( C )A. host name, IP addressB. host name, MAC addressC. IP address, MAC addressD. broadcast address, IP address8. The value of Preamble field in Ethernet frame structure is ( C)A. 10101010 10101010……10101010 11111111B. 10101011 10101011……10101011 10101011C. 10101010 10101010……10101010 10101011D. 10101010 10101010……10101010 101010109. In CSMA/CD, the adapter waits some time and then returns to sensing thechannel. In the following four times, which one is impossible? ( D)A. 0 bit timesB. 512 bit timesC. 1024 bit timesD. 1028 bit times10. The principal components of PPP include but not( D ).A. framingB. physical-control protocolC. link-layer protocolD. network-layer protocol11. Consider the data D is 01110010001, if use even parity checking approach, theparity bit is( ① ), if use odd parity checking approach, the parity bit is( ② ). ( D )A. ① 0 ② 1B. ① 0 ② 0C. ① 1 ② 1D. ① 1 ② 012. In the following four descriptions, which one is not correct? (B )A. Switches can interconnect different LAN technologies.B. Hubs can interconnect different LAN technologies.C. There is no limit to how large a LAN can be when switches are used tointerconnect LAN segments.D. There is restriction on the maximum allowable number of nodes in a collisiondomain when hubs are used to interconnect LAN segments.13. Which of the following devices is not a plug and play device? ( B )A. hubB. routerC. switchD. repeater14. Which device has the same collision domain? ( A )A. HubB. SwitchC. RouteD. Bridge15. In data link-layer, which protocol is used to share bandwidth? ( D)A. SMTPB. ICMPC. ARPD. CSMA/CD16. When two or more nodes on the LAN segments transmit at the same time, therewill be a collision and all of the transmitting nodes well enter exponential back-off, that is all of the LAN segments belong to the same( A ).A. collision domainB. switchC. bridgeD. hub17. In the following four descriptions about PPP, which one is not correct? ( D )A. PPP is required to detect and correct errors.B. PPP is not required to deliver frames to the link receiver in the same order inwhich they were sent by the link sender.C. PPP need only operate over links that have a single sender and a single receiver.D. PPP is not required to provide flow control.18. For ( A ) links that have a single sender at one end of the link and a single receiverat the other end of the link.A. point-to-pointB. broadcastC. multicastD. all of the above19. With(B )transmission, the nodes at both ends of a link may transmit packets at thesame time.A. half-duplexB. full-duplexC. simplex(单工)D.synchronous20. Which of the following is wrong? ( A )A. ARP table is configured by a system administratorB. ARP table is built automaticallyC. ARP table is dynamicD. ARP table maps IP addresses to MAC addresses21. In LAN, if UTP is used, the common connector is (C ).A. AUIB. BNCC. RJ-45D. NNI22. Which of the following four descriptions about MAC addresses is wrong? ( C )A. a MAC address is burned into the adapter’s ROMB. No two adapters have the same addressC. An adapter’s MAC address is dynamicD. A MAC address is a link-layer address23. In the CSMA/CD protocol, what condition on the transmission delay and thepropagation delay has to be satisfied to guarantee that a node always detects a collision? BA. B.C. D.。

川大软院计网选择题答案

川大软院计网选择题答案C h a p t e r4(含答案)(总5页)--本页仅作为文档封面，使用时请直接删除即可----内页可以根据需求调整合适字体及大小--CHAPTER 4: NETWORK LAYERof the following groups belongs to network layer protocol_____D____, TCP andUDP, IP, and UDP, IMAP andIP, BGP, and RIP3-PDU is named as ____C_____a datagram network, the forwarding decision is based on the valueof the ____B field in the packet header.addressaddressof the choices areblocking happens on ____A_____portportfabricsof aboveno free buffers in router, the arriving packets will be: Anormal IP packet forwarding at a router, which of the following packet fields are updated____C____IPaddressIP addressport numberof the following IP address doesn’t belong to the network______D___are given an IP network of and told that you need to separate this network into sub networks that can support a maximum of 30 hosts per subnet. This will help alleviate congestion on thenetwork. What subnet mask can you use to create the subnetsnecessary to meet the given criteria___C______IP datagram of 1500 bytes (20 byte of IP header plus 1480 bytes of IP payload) arrives at a router and must be forwarded to a link with an MTU of 500 bytes. Thus the router has to fragment the datagram. To the last fragment, the value of offset should be _____D____is a ____C_____ protocol.unreliablereliableunreliablereliableICMP message type is the basis for the Traceroute utility?B RequestexpiredUnreachableReassembly Time Exceedin the path are not allowed to _________________B__________.the packet they receivesource or destination addressthe packetof the choices are correctallows a site to use a set of private addresses for internal communication and a set of global Internet addresses forcommunication with the rest of the world.of the choices are correctmany bits are there in IPv6______C___CIDR notation, which of the following networks contains host is the limited broadcast address corresponding to the nodewith the following IP address: of the aboveclassful IP addressing, how many network bits does have?Ais the broadcast IP address for / 26Da networkFrom IP address perspective they can physically reach each other without intervening router and the device interfaces with: C IP addressTCP port #network part of IP addresshost part of IP addressInternet’s network layer has three major components, the first component is the IP protocol, the second component is therouting protocol, the final componenttranslationaddressing assigns an address to the network address for this network （）are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101.Their checksum isA____.use of hierarchy in routing tables can __A______ the size of the routing tables.reduce nor increaseof the choices are correctof the following protocol doesn’t belong to intra-AS routing protocol_____B____of the following protocol belongs to intra-AS routing protocol ______A___(DistanceVector)(Link State)OSPF network, a ____B_____ belongs to both an area and the backbone.routerborder routerrouterrouteris an inter-domain routing protocol using path vector routing.of the choices are correctuses the services of ___C____.of the choices are correctRouting Information Protocol (RIP) is an intra-domain routing based on _______A__ routing.vectorstatevectorof the aboveof the following algorithm has the so called count-to-infinity problem?Calgorithmalgorithmvector algorithmof the above。

四川大学(软件)计算机组成与体系结构判断题

A byte is 8 bits, but a word may vary in size (16-bits, 32-bits, etc.) from one architecture to another.（√）一个字节是8位，但是一个字的大小可能会有所不同（16位，32位等），从一个架构到另一个架构The term endian refers to the byte ordering, or the way a computer stores the bytes of a multiple-byte data element.（√）术语位端指的是字节排序，或者计算机存储多字节数据元素字节的方式。

Accumulator architectures use sets of general purpose registers to store operands（√）累加器体系结构使用一组通用寄存器来存储操作数A two pass assembler generally creates a symbol table during the first pass and finishes the complete translation from assembly language to machine instructions on the second.（√）双程汇编程序通常会在第一遍中创建一个符号表，并在第二个汇编语言完成对机器指令的完整翻译。

The MAR, MBR, PC and IR registers in MARIE can be used to hold arbitrary data values.（×）MARIE中的MAR，MBR，PC和IR寄存器可用于保存任意数据值。

A branch instruction changes the flow of information by changing the PC. （√）分支指令通过改变PC来改变信息流。

四川大学软件工程课后习题答案

第一章1.1举出至少5个例子来说明“意外效应法则”在计算机软件方面的应用。

答：典型的例子包括使用“数字汽车仪表板”的软件，赋予高科技，高品质的图像的软件；如广泛的消费类电子产品的软件；个人电脑，工业仪器仪表和机器的软件。

软件分化出的在电子商务方面的应用。

1.2举例说明软件对社会的影响（包括正面影响和负面影响）。

答：这是一个很好的课堂讨论问题（如果时间允许），而不是专注于老生常谈的（但很重要）隐私问题，生活质量等问题。

您可能想要讨论关于”技术恐惧“方面的问题，软件也许会使它恶化但也可能减少”技术恐惧“。

另一个有趣的方面是使用诺依曼的“风险”列在SEN中做重点讨论。

你也可以考虑基于软件的“现金”经济，新模式的互动娱乐，虚拟现实，电子商务等方面来思考软件对社会的影响。

1.3针对1.1节提出的5个问题，请给出你的答案，并与同学讨论。

答：软件需要如此长的开发时间：a）设施不上线b）开发工具并不如预期般运作c）客户提出的新要求，需要重新设计和返工d）产品依赖于政府的规定，被意外更改。

e）严格的要求，与现有系统的兼容性需要超过预期更多的测试，设计和实现。

f）多个操作系统下运行的任务需求比预期需要更长的时间。

g）软件项目风险管理比预期需要更多的时间。

h）依赖的技术仍处于开发阶段，从而延长日程安排。

开发成本高：a）比当时预期低得令人无法接受的质量，需要进行更多的测试，设计和实施工作。

b）制定了错误的软件功能需要重新设计和实施。

c）开发错误的用户界面，而导致重新设计和实施。

d）开发了不需要的额外的软件功能而延长了开发日程安排。

在将软件交付顾客使用之前，我们无法找到所有错误：a）产品依赖于政府监管，意外而改变。

b）产品技术标准草案，会意外更改。

c）有时会在项目后期添加新的开发人员。

d）因为团队内的冲突有时会导致沟通不畅，而产生糟糕的设计。

e）破坏高效调度产生的项目管理成果和无效的规划f）有时装备部件质量差，导致额外的测试，设计和集成工作和管理额外的客户关系。

2021年四川大学软件工程专业《计算机组成原理》科目期末试卷B(有答案)

2021年四川大学软件工程专业《计算机组成原理》科目期末试卷B（有答案）一、选择题1、局部性原理是一个持久的概念，对硬件和软件系统的设计和性能都有着极大的影响。

局部性通常有两种不同的形式：时间局部性和空间局部性。

程序员是否编写出高速缓存友好的代码，就取决于这两方面的问题。

对于下面这个函数，说法正确的是（）。

int sumvec(int v[N]){int i, sum=0;for(i=0;i<N;i++)sum+= v[i]eturn sum;}A.对于变量i和sum，循环体具有良好的空间局部性B.对于变量i、sum和v[N]，循环体具有良好的空间局部性C.对于变量i和sum，循环体具有良好的时间局部性D.对于变量i、sum和v[N]，循环体具有良好的时间局部性22、主存储器主要性能指标有（）。

1.存储周期Ⅱ.存储容量Ⅲ.存取时间Ⅳ.存储器带宽A.I、IⅡB.I、IⅡ、IVC. I、Ⅲ、lVD.全部都是3、在原码两位乘中，符号位单独处理，参加操作的数是（）。

A.原码B.绝对值的补码C.补码D.绝对值4、某计算机字长为32位，按字节编址，采用小端（Litle Endian）方式存放数据。

假定有一个double型变量，其机器数表示为1122334455667788H，存放在00008040H开始的连续存储单元中，则存储单元00008046H中存放的是（）。

A.22HB.33HC.66HD.77H5、常用的（n，k）海明码中，冗余位的位数为（）。

A.n+kB.n-kC.nD.k6、总线按连接部件不同可分为（）。

A.片内总线、系统总线、通信总线B.数据总线、地址总线、控制总线C.主存总线I/O总线、DMA总线D.ISA总线、VESA总线、PCI总线7、某同步总线采用数据线和地址线复用方式，其中地址/数据线有32根，总线时钟频率为66MHz，每个时钟周期传送两次数据（上升沿和下降沿各传送一次数据），该总线的最大数据传输率（总线带宽）是（）。

2022年四川大学软件工程专业《计算机组成原理》科目期末试卷B(有答案)

2022年四川大学软件工程专业《计算机组成原理》科目期末试卷B（有答案）一、选择题1、某计算机主存按字节编址，由4个64M×8位的DRAM芯片采用交叉编址方式构成，并与宽度为32位的存储器总线相连，主存每次最多读写32位数据。

若double型变量x 的主存地址为80400lAH，则读取x需要的存储周期数是（）。

A.1B.2C.3D.42、某计算机使用4体交叉编址存储器，假定在存储器总线上出现的主存地址（十进制）序列为8005，8006，8007，8008，8001，8002，8003，8004，8000，则可能发生访存冲突的地址对是（）。

A.8004和8008B.8002和8007C.8001和8008D.8000和80043、完整的计算机系统应该包括（）。

A.运算器、存储器、控制器B.外部设备和主机C.主机和应用程序D.主机、外部设备、配套的软件系统4、（）可区分存储单元中在放的是指令还是数据。

A.存储器B.运算C.用户D.控制器5、指令寄存器的位数取决（）。

A.存储器的容量B.指令字长C.机器字长人D.存储字长6、总线的通信控制主要解决（）问题。

A.由哪个主设备占用总线B.通信双方如何获知传输开始和结束C.通信过程中双方如何协调配合D.B和C7、总线按连接部件不同可分为（）。

A.片内总线、系统总线、通信总线B.数据总线、地址总线、控制总线C.主存总线I/O总线、DMA总线D.ISA总线、VESA总线、PCI总线8、某计算机的指令流水线由4个功能段组成，指令流经各功能段的时间（忽略各功能段之间的缓存时间）分别为90ns，80ns、70ns和60ns，则该计算机的CPU时钟周期至少是）（）。

A.90nsB.80nsC.70nsD.60ns9、从一条指令的启动到下一条指令启动的时间间隔称为（）A.时钟周期B.机器周期C.节拍D.指令周期10、为提高存储器的存取效率，在安排磁盘上信息分布时，通常是（）.A.存满一面，再存另一面B.尽量将同一文件存放在一个扇区或相邻崩区的各磁道上C.尽量将同一文件存放在不同面的同一磁道上D.上述方法均有效11、中断服务程序的最后一条指令是（）。

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In the following options, which does not define in protocol ( D )A the format of messages exchanged between two or more communicatingentitiesB the order of messages exchanged between two or more communicatingentitiesC the actions taken on the transmission of a message or other eventD the transmission signals are digital signals or analog signalsIn the following options, which is defined in protocol ( A )A the actions taken on the transmission and/or receipt of a message or othereventB the objects exchanged between communicating entitiesC the content in the exchanged messages\D the location of the hostsAn application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes (C ).A flow controlB congestion-controlC reliable data transferD connection-oriented serviceThe Internet’s connection-oriented service has a name, it is ( A ).A TCP$B UDPC TCP/IPD IPThe Internet’s connectionless service is called ( B ).A TCPB UDPC TCP/IPD IP.Which of the following nodes belongs to the network coreCA. a Web ServerB. a Host with Win2003 ServerC. a Router with NAT serviceD. a Supernode on Skype NetworkIn the Internet, the equivalent concept to end systems is ( )A.A hostsB serversC clientsD routers）In the Internet, end systems are connected together by ( C ).A copper wireB coaxial cableC communication linksD fiber opticsEnd systems access to the Internet through its (C ).A modemsB protocolsC ISP，D socketsIn the following options, which belongs to the network core ( B )A end systemsB routersC clientsD serversEnd systems, packet switches, and other pieces of the Internet, run ( D ) that control the sending and receiving of information within the Internet.A programs#B processesC applicationsD protocolsThe internet allows ( D ) running on its end systems to exchange data with each other.A clients applicationsB server applicationsC P2P applicationsD distributed applications.The protocols of various layers are called ( A ).A the protocol stackB TCP/IPC ISPD network protocolIn the OSI reference model, the upper layers of the OSI model are, in correct orderD ASession, application, presentationBSession, presentation, applicationCSession, application, presentation, physical`DApplication, presentation, sessionThe lower layers of the OSI model are, in correct orderDAphysical, system, network, logicalBphysical, logical, network, systemCphysical, transport, network, data linkDphysical, data link, network, transportThe Internet Protocol (IP) generally corresponds to which OSI layerA ANetwork (layer three)^BTransport (layer four)CData link (layer two)DSession (layer five)What layer of the OSI model is designed to perform error detection functionsB APhysicalBData linkCNetworkDtransport。

Which of the following protocol layers is not explicitly part of the Internet Protocol Stack _____B____A. application layerB. session layerC. data link layerD. transport layerThe 5-PDU is called__A_A. messageB. segmentC. datagramD. frameThe Internet’s network layer is responsible for moving network-layer packets known as B( ) from one host to another.A frame·B datagramC segmentD messageTransport-layer packets are called:BA. messageB. segmentC. datagramD. frameThe units of data exchanged by a link-layer protocol are called ( A).A FramesB Segments:C DatagramsD bit streamsThere are two fundamental approaches to building a network core, ( B ) and packet switching.A electrical current switchingB circuit switchingC data switchingD message switching-Datagram networks and virtual-circuit networks differ in that ( C ).A datagram networks are circuit-switched networks, and virtual-circuitnetworks are packet-switched networks.B datagram networks are packet-switched networks, and virtual-circuitnetworks are circuit-switched networks.C datagram networks use destination addresses and virtual-circuit networksuse VC. numbers to forward packets toward their destination.D datagram networks use VC. numbers and virtual-circuit networks usedestination addresses to forward packets toward their destination.(A ) means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.A Store-and-forward transmissionB FDMC End-to-end connection￥D TDMIn ( C ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.A packet-switchedB data-switchedC circuit-switchedD message-switchedIn ( A ) networks, the resources are not reserved; a session’s messages use the resources on demand, and as a consequence, may have to wait for access to communication link.A packet-switched>B data-switchedC circuit-switchedD message-switchedIn a circuit-switched network, if each link has n circuits, for each link used by the end-to-end connection, the connection gets ( A) of the link’s bandwidth for the duration of the connection.A a fraction 1/nB allC 1/2D n times、For (C ), the transmission rate of a circuit is equal to the frame rate multiplied by the number of bits in a slot.A CDMAB packet-switched networkC TDMD FDMThe network that forwards packets according to host destination addresses is called ( D) network.A circuit-switchedB packet-switched*C virtual-circuitD datagramThe network that forwards packets according to virtual-circuit numbers is called ( C ) network.A circuit-switchedB packet-switchedC virtual-circuitD datagramThe time required to propagate from the beginning of the link to the next router is ( C).！A queuing delayB processing delayC propagation delayD transmission delayProcessing delay does not include the time to (B ).A examine the packet’s headerB wait to transmit the packet onto the linkC determine where to direct the packetD check bit-error in the packet—In the following four descriptions, which one is correct ( C)A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensity decreases.C If the traffic intensity is close to zero, the average queuing delay will be closeto zero.D If the traffic intensity is close to one, the average queuing delay will be closeto one.Suppose, a is the average rate at which packets arrive at the queue, R is the transmission rate, and all packets consist of L bits, then the traffic intensity is ( B ),A LR／aB La／R【C Ra／LD LR／aSuppose there is exactly one packet switch between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 and R2, respectively. Assuming that the switch uses store-and-forward packet switching, what is the total end-to-end delay to send a packet of length L(Ignore queuing delay, propagation delay, and processing delay.) ( A )A L/R1＋L/R2B L/R1C L/R2D none of the above@We are sending a 30 Mbit MP3 file from a source host to a destination host. Suppose there is only one link between source and destination and the link has a transmission rate of 10 Mbps. Assume that the propagation speed is 2 * 108 meters/sec, and the distance between source and destination is 10,000 km. Also suppose that message switching is used, with the message consisting of the entire MP3 file. How many bits will the source have transmitted when the first bit arrives at the destinationCA. 1 bitB. 30,000,000 bitsC. 500,000 bitsD. none of the aboveIn the following entries, which is not a kind of access network(D )A residential accessB company accessC wireless accessD local accessThe following technologies may be used for residential access, exceptDA. HFCB. DSLC. Dial-up modemD. FDDIWhich kind of media is not a guided media ( D)A twisted-pair copper wireB a coaxial cableC fiber opticsD digital satellite channel。