计算机等级考试四级笔试试卷及答案(一)（Computer rank examination four level written examination paper and answer (1)）First, the multiple-choice questions (70 questions, 1 points for each subject, 70 points out of the question). Among them, (1) - (55), entitled Chinese title, (56) - (70) entitled English titleOf the following four options, only one option is correct in the A, B, C, and D). Please insert the correct options for filling in the corresponding position on the answer sheet, not on the test paper score.(1) the input variables or gate for X1 and X2, the output variable is Y, the output of Y is 1 X1 and the value of X2 isA) 0, 0, B) 0, 1, C) 1, 0, D) 1, 1(2) if the binary original code for -0.0101, its complement(A) -0.0101, B) 0.0101, C) 1.1011, D) 1.1010(3) the so-called instruction cycle means(A) the time taken to fetch instructions and fetch operands, B) to execute instructions and store the results of the operationC) fetch operand and execution time D) fetch instruction and execute instruction time(4) which one of the following applies to the queue?A) expression evaluation B) implementation of heap sorting algorithm(C) hierarchical sequence of tree traversal algorithm D) implementation of two tree symmetric sequential traversal algorithm(5) in the following statement about the generalized tables, what is correct is.(A) a generalized table is a finite sequence consisting of 0 or more single elements or sub tables(B) at least one element of a generalized table is a child table(C) a generalized table cannot be its own child tableD) a generalized table cannot be an empty table(6) sorting the files of the N records quickly, and the required storage space isA) O () B) O C) O () D) O ()(7) the directed graph below. How many different topological sequences can the nodes be arranged into?A) 3, B) 5, C) 7, D) 9(8) as follows, a 5 order B tree, the B tree is now 2. After deleting key 38 from the B tree, the second layers of the B tree have a number of nodesA) 6, B) 7, C) 8, D) 9(9) let G = be any group, and the following conclusion is not necessarily trueA) a, B, x, A, equation a * x = B the solution is x = A-1 * BB) a, B, C, A, if a * b = a * C, then B = CC) a, B, A, then a * b = b * a(D) a, B, C, A, then (a * b) * C = a * (b * c)(10) let A, B be any two set, known A-B = A, the following conclusion1. B-A = B B = A 2. B A 3.Which of these is true?(A) only one B) only II C) only III D) I and II(11) set A=1,2, R = x, y, A, and x+y3, then R is on AA) reflexive, but not symmetric B) reflexive and symmetricC) symmetric, but not reflexive, D) neither reflexive nor symmetrical(12) set F (x):x is human, G (x):x, have been to mars. Which of the following formulas are the symbolic forms of the proposition that no one has been to Mars?(A) II and II B) II and III C) only III D) all(13) let V1 set the cut set of undirected connected graph G, remember G, delete V1, the number of connected branches is p (G-, V1) = k, which must be true in the following propositionsA) k = 2 B) k = 3 C) k = 2, k = 2 D)(14) the number of edges of any undirected simple graph of order n should be satisfied by MA M = n-1) B) M = n (n-1) /2 C) m D M = n = n)(15) which of the following operating systems should be used in an accurate guided missile?(A) batch operating system B) personal computer operating system(C) real time operating system D) network operating system(16) which of the following program status words (PSW) determines whether the operating system program can be executed?A) protection bit B) mask bitC) condition bit D) CPU status bit(17) a process that cannot run because it has not been printedA) ready state B) running stateC) wait state D) backup status(18) which of the following problems only involves process exclusive problem?A) relay race on track and fieldB) a process reads a file, and a process writes a fileC) a producer and a consumer pass products through a buffer(D) the collaboration between a bus driver and a conductor(19) assuming that the system is in the following security state, the number of system remaining resources is 2. Which of the following process sequences is a security sequence?The process accounts for the maximum number of resources requiredP1 12P2 35P3 48P4 57(A) P1, P2, P3, P4, B), P1, P3, P4, P2(C) P3, P2, P4, P1, D), P3, P1, P4, P2(20) the page table page virtual storage management plays an important role, which indicates that the page is in memory or on disk page table entry isA) interrupt bit B) memory block number C) access bit D) modify bit(21) in the UNIX system, if the creator of the file X wishes to read and write the file X to all users (including itself), but cannot execute X, which of the following commands can be used to complete?A) chown