問題詳情
13)从表中选择字段形成新关系的操作是
(A)选择
(B)连接
(C)投影
(D)并
(A)选择
(B)连接
(C)投影
(D)并
參考答案
答案:C
難度:適中0.5
統計:A(0),B(0),C(0),D(0),E(0)
內容推薦
- ——Play you missed the lecture on nuclear pollution。——I it,but I was busy preparing for a job inte
- -Shall has a gift for creat an atmosphere for her students allow them to communicate freely with
- (A) through (B) for (C) before (D) with
- 12)释放和关闭表单的方法是(A)Release (B)Delete (C)LostFocus (D)Destory
- (A) reality (B) fact (C) challenge (D) wonder
- It was April 29,2001 Prince William and Kate Middleton walked into the palace hall of the wedding
- She has a gift for creating an atmosphere for her students ____ allows them to communicate freel
- (A) Naturally (B) Gradually (C) Luckily (D) Clearly
- 2)下列叙述中正确的是(A)循环队列有队头和队尾两个指针,因此,循环队列是非线性结构(B)在循环队列中,只需要队头指针就能反应队列中元素的动态变化情况(C)在循环队列中,只需要队尾指针就能反应队列中元
- Last month,the Japanese government expressed their thanks for the aid they From ChinA(A)receive (
內容推薦
- The lack of eco-friendly habits among the public is thought to be a major of global climate chang
- ——My teacher says she’s canceling the class play.I just can’t understanD—— .You were looking forw
- (A) pressure (B) judgement (C) influence (D) confidence
- 14)Modify Command命令建立的文件的默认扩展名是(A)prg (B)app (C)cmd (D)exe
- 6)在软件开发中,需求分析阶段可以使用的工具是(A)N-S图 (B)DFD图 (C)PAD图 (D)程序流程图
- The difference in thinkness and weight from the earlier version makes the iPad 2 more comfortable
- 第二节 完形填空(共20小题;每小题5分,满分30分)阅读下面短文,从短文后给题所给的四个选项(A、B、C、D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。Diana Velex d
- (A) put away (B) depend on (C) learn about (D) look into
- 15)说明数组后,数组元素的初值是(A)整数0 (B)不定值 (C)逻辑真 (D)逻辑假
- 7)在面向对象方法中,不属于“对象”基本特点的是(A)一致性 (B)分类性 (C)多态性 (D)标识唯一性
- I’d prefer to my judgement until I find all the evidence.(A)show (B) express (C)pass (D)reserve
- (A) goal (B) memory (C) choice (D) problem
- 3)在长度为n的有序线性表中进行二分查找,最坏情况下需要比较的次数是(A)O(N) (B)O(n2) (C)O(log2n) (D)O(n log2n)
- (A) around (B) back (C) ahead (D) out
- 8)一间宿舍可住多个学生,则实体宿舍和学生之间的联系是(A)一对一 (B)一对多 (C)多对一 (D)多对多
- -It’s nice.Never before such a special drink!-I’m glad you like it.(A)I have had (B) I had (C) ha
- (A) aontinue (B) choose (C) change (D) lose
- 4)下列叙述中正确的是(A)顺序存储结构的存储一定是连续的,链式存储结构的存储空间不一定是连续的(B)顺序存储结构只针对线性结构,链式存储结构只针对非线性结构(C)顺序存储结构能存储有序表,链式存储结
- 16)扩展名为mpr的文件是(A)菜单文件 (B)菜单程序文件 (C)菜单备注文件 (D)菜单参数文件
- 9)在数据管理技术发展的三个阶段中,数据共享最好的是(A)人工管理阶段 (B)文件系统阶段(C)数据库系统阶段 (D)三个阶段相同
- (A) demanded (B) decided (C) agreed (D) hesitated
- 5)数据流图中带有箭头的线段表示的是(A)控制流 (B)事件驱动 (C)模块调用 (D)数据流
- 17)下列程序段执行以后,内存变量y的值是x=76543y=0DO WHILE x>0y=x%10+y*10x=int(x/10)ENDDO(A)3456 (B)34567 (C)7654 (D
- 10)有三个关系R、S和T如下:A B Cm 1 3R S TA Bm 1n 2B C1 33 5由关系R和S通过运算得到关系T,则所使用的运算为(A)笛卡尔积 (B)交 (C)并 (D)自然连接
- (A) advance (B) start (C) suffer (D) work