【单选题】
I asked a passenger sitting beside me if our train was the Westlake Express train, and he said he ___ of it.
A. not even heard
B. had not even heard
C. even not heard
D. ever had not heard
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相关试题
【单选题】
Whatever you say in the paper has to ___ your own thinking; hence simply repeating the professor’s opinions or whatever is in the readings will not get you very far.
A. ignore
B. arouse
C. reflect
D. release
【单选题】
We are sorry to know that they did not succeed ___ the project for lack of necessary funds.
A. to fulfill
B. to have fulfilled
C. in fulfilling
D. with fulfilling
【单选题】
It is surprising that fewer students were prepared to undertake the ___ to hand in written work on a regular basis, or to study over long periods.
A. engagement
B. commitment
C. authority
D. aspiration
【单选题】
Emily felt hurt and ___ by a close friend who had borrowed a considerable sum of money to pay for a house and then took it as a gift, never thinking of giving back the money.
A. conflicted
B. curbed
C. swollen
D. betrayed
【单选题】
In 1988 the old system was ___ in the country and a new system was introduced to take effect in 1990.
A. transmitted
B. abolished
C. assumed
D. compensated
【单选题】
We should not ___ ourselves to the classroom. We should go out of the classroom, see the world and talk to others as much as we can.
A. entertain
B. confine
C. assign
D. involve
【单选题】
I have always been grateful ___ Fred __the generous and helpful information when I was at the crossroads.
A. to … for
B. to … with
C. for … with
D. for … to
【单选题】
I think we both need to ___ the past, be happy about what we had for a time, learn from our experiences, and move on from there.
A. let go of
B. give authority to
C. make sense of
D. keep up with
【单选题】
My brother and I managed to ___ with each other and we soon made peace after a week’s quarrel.
A. heal
B. reconcile
C. respond
D. advocate
【单选题】
The two robbers in a stolen car tried to ___ a police roadblock (路障), but faile D.
A. break in
B. break off
C. break up
D. break through
【单选题】
Because of his long illness, Lee’s English level had dropped, but he was determined to ___ the other students by working harder.
A. put up with
B. catch up with
C. get along with
D. fill up with
【单选题】
We appreciate your efforts in making changes in your schedule and think that this new arrangement is now ___ to us.
A. agreeable
B. sustainable
C. portable
D. indispensable
【单选题】
The woman who died in a car crash last Saturday in the suburbs has been ___ as Kate Johnson, a 25-year-old office clerk.
A. justified
B. identified
C. notified
D. classified
【单选题】
My nephew failed in the College Entrance Examination, and we were all very sorry that he did not ___ to the university.
A. take it
B. get it
C. make it
D. succeed it
【单选题】
Almost half of that group will experience stress ___ enough to call for professional help.
A. tense
B. moderate
C. bearable
D. intense
【单选题】
If you grow too fast your entire economy could completely shut down and bring growth to a(n) ___.
A. halt
B. cease
C. peak
D. epidemic
【单选题】
I tried my best to drive inside in order to avoid the edges that might make me ___ the steep slope.
A. slip down
B. settle down
C. bring down
D. turn down
【单选题】
When the driver heard that there was a bomb on the bus, he immediately ___ to the side of the highway and radioed the police.
A. put out
B. took off
C. pulled over
D. slipped off
【单选题】
She was very ___ to become a manager in our customers’ office, but finally accepted our offer.
A. eager
B. intelligent
C. ridiculous
D. reluctant
【单选题】
In the race, it looked as if he would be the first, but then another young man who was close behind him put on speed and ___ by a few seconds.
A. beat him for it
B. beat him to it
C. beat him up
D. beat it to him
【单选题】
It is really helpful to have someone like you that we can ___ and count on during difficult times.
A. lean on
B. get to
C. hang on
D. get by
【单选题】
Women have a greater ability to ___ names with faces than men do, and they are also better at recalling lists.
A. associate
B. compare
C. engage
D. involve
【单选题】
He was always ready to help others and managed to ___ his friends ____being hurt.
A. expose … to
B. confine …to
C. restrict … from
D. shield … from
【单选题】
Older people are less likely to be ___ their negative emotions (情绪) and more likely to focus on the positive.
A. reserved for
B. caught up in
C. beat up to
D. counted on
【单选题】
I don’t have any bandage, so I have to ___ pressure to the wound to keep the bleeding down.
A. apply
B. involve
C. fulfill
D. establish
【单选题】
It is important that whichever candidate (候选人) is picked the loser should accept the defeat ___.
A. in advance
B. with great pride
C. with good grace
D. in large part
【单选题】
___ that new homes cost more than older homes, but that is not true across the country anymore.
A. It used to be
B. It is used to be
C. It used to being
D. It is used to being
【单选题】
The boss ___ his employees to work longer hours as the company is dreadfully short of staff at present.
A. called on
B. signed up
C. cared for
D. set up
【单选题】
The president’s visit and ___ discussions led to a plan that aimed to improve the trade relations between the two countries.
A. emerging
B. subsequent
C. consequent
D. Submerging
【单选题】
The author ___ his general idea mainly through statistics and results obtained from a survey (调查) about auto customer services in the United States.
A. assumes
B. engages
C. illustrates
D. represents
【单选题】
People in this town starved, several buildings were bombed and crime ___ because you had to steal to eat.
A. eroded
B. reflected
C. released
D. soared
【单选题】
Olympic recognition for bodybuilding (健美) remains ___ since some argue that bodybuilding is not a sport because the actual contest does not involve the same sort of efforts as “real” sports.
A. controversial
B. conventional
C. characteristic
D. influential
【单选题】
Tom tried to justify his absence from the meeting by ___ that he had been ill that day.
A. admitting
B. advocating
C. claiming
D. citing
【单选题】
___ the huge financial benefits, biological companies have been rushing to set up laboratories and new research projects.
A. Aware
B. Aware of
C. Not aware
D. Not aware of
【单选题】
Unfortunately, ___ lack of funds, the studies he began just two months ago, had to be ended early.
A. out of
B. in addition to
C. owing to
D. to begin with
【单选题】
With a good command of English, he soon got ___ to working with British people.
A. accustomed
B. consistent
C. relevant
D. responsible
【单选题】
What needs to be ___ here is that language and culture interact, and that understanding of one requires understanding of the other.
A. altered
B. stressed
C. aroused
D. committed
【单选题】
Policies and organizations must be created to meet workers’ hopes, and to ___ new problems that inevitably arise between workers and managers.
A. compromise
B. ensure
C. undermine
D. resolve
【单选题】
To keep the wheels of industry turning, we produce consumer goods in endless quantities, and, in the process, are rapidly ___ our natural resources.
A. ignoring
B. collapsing
C. enduring
D. exhausting
【单选题】
As a person who loves peace, he is committed ___ realizing peace between countries.
A. of
B. about
C. for
D. to
推荐试题
【单选题】
在关系模型中,一个关键字 ___
A. 可由多个任意属性组成
B. 至多由一个属性组成
C. 可由一个或多个其值能唯一标识该关系模式中任何元组的属性组成
D. 以上都不是
【单选题】
同一个关系模型的任两个元组值___
A. 不能全同
B. 可全同
C. 必须全同
D. 以上都不是
【单选题】
一个关系中的各个元组___
A. 前后顺序不能任意颠倒,一定要按照输入的顺序排列
B. 前后顺序可以颠倒,不影响库中的数据关系
C. 前后顺序可以任意颠倒,到排列顺序不同,统计处理的结果就可能不同
D. ”前后顺序不能任意颠倒,一定要按照关键字段值的顺序排列
【单选题】
设学生关系模式为:学生(学号,姓名,性别,成绩,专业)则该关系模式的主码是___
A. 姓名
B. 学号,姓名
C. 学号
D. 学号,姓名,年龄
【单选题】
有一个关系:学生(学号,姓名,系别)规定学号的值域是8个数字组成的字符串,这一规则属于()
A. 实体完整性约束
B. 参照完整性约束
C. 用户自定义完整性约束
D. 关键字完整性约束
【单选题】
已知关系1:厂商(厂商号,厂名),关系1的主码的为厂商号;关系2:产品(产品号,颜色,厂商号),关系2的主码为产品号,外码为厂商号。
假设两个关系中已经存在如表2-14和表2-15所示的元组,若再往产品关系中插入如下元组:I(P03,红,C02),II(P01,蓝,C01), I I I(P04,白C04),IV(P05, 黑,null)
表2-14厂商
厂商号 厂名
C01 宏达
C02 立仁
表2-15产品
产品号 颜色 厂商号
P01 红 C01
P02 黄 C03
能够插入的元组是()
A. I,I I,I I I
B. I,I I
C. I,II
D. I,IV
【单选题】
在关系S (NAME, SNO, DEPART)中规定DEPART属性只能是计算机。这规定属于___
A. 用户自定义完整性
B. 参照完整性
C. 实体完整性
D. 固定完整性
【单选题】
在下面的两个关系中,职工号和部门号分别为职工关系和部门关系的主码。职工(职工号,职工名,部门号,职务,工资)郁门(部门号,部门名,部门人数:工资总额)在这两个关系的属性中,只有一个属性是外码,它是___
A. 职工关系的职工号
B. 职工关系的部门号
C. 部门关系的部门号
D. 部门关系的部门名
【填空题】
2.在一个实体表示的信息中,称___为关键字
【填空题】
3.已知“系【系编号,系名称,系主任,电话,地点】”和“学生【学号,姓名,性别,入学日期,专业,系编号】”两个关系,“系”关系的主关键字是___,“学生”关系的主关键字是___,外关键字是___
【填空题】
4.在关系数据库中,二维表称为一个___,表的每一行称为___,表的每一列称为___。
【填空题】
5.关系数据库是以___为基础的数据库,利用___描述现实世界,一个关系既可以描述___,也可以描述___
【填空题】
6.___运算是从一个现有的关系中选取某些属性,组成一个新的关系。
【单选题】
1.下列不属于数据库设计的任务是___。
A. 进行需求分析
B. 设计数据库管理系统
C. 设计数据库逻辑结构
D. 设计数据库物理结构
【单选题】
数据库物理设计完成后,进去数据库实施阶段,一般不属于实施阶段的工作的是
A. 建立库结构
B. 系统调试
C. 加载数据
D. 扩充功能
【单选题】
数据流图是用于数据库设计中___阶段的工具。
A. 需求分析
B. 概念结构设计
C. 物理设计
D. 逻辑结构设计
【单选题】
有关系模式“学生【学号,课程号,名次】”,若每一名学生每门课程有一定的名次,每门课程每一名次只有一名学生, 则以下叙述中错误的是___。
A. (学号,课程号)和(课程号,名次)都可以作为候选码
B. 只有(学号,课程号)能作为候选码
C. 关系模式属于第3范式
D. 关系模式属于BCNF
【单选题】
4.关系数据库规范化理论是为解决关系数据库中的___问题而引入的。
A. 插入、更新、删除和数据冗余
B. ,提高查询速度
C. 减少数据操作的复杂性
D. 保证数据的安全性和完整性
【单选题】
若关系模式R 【A, B】已属于3NF,下列说法中___是正确的。
A. 它一定消除了插入和删除异常
B. 可能存在一定的插入和删除异常
C. 一定属于BCNF
D. A和C都是
【单选题】
关系模型中的关系模式至少满足___
A. 1NF
B. 2NF
C. 3NF
D. BCNF
【单选题】
在关系模式中,如果属性A和B存在一对一的联系,则说___。
A. A→B
B. B→A
C. A←→B
D. 以上都不是
【单选题】
在数据库设计中,将E-R图转换成关系数据模型的过程属于___。
A. 需求分析阶段
B. 逻辑设计阶段
C. 概念设计阶段
D. 物理设计阶段
【单选题】
下列关于关系数据库规范化理论的描述中, 不正确的是___。
A. 规范化理论提供了判断关系模式优劣的理论标准
B. 规范化理论提供了判断关系数据库管理系统优劣的理论标准
C. 规范化理论对于关系数据库设计具有重要指导意义
D. 规范化理论对于其他模型的数据库的设计也有重要指导意义
【单选题】
有关系:教学【学号、教工号、课程号】,假定每个学生可以选修多门课程,每门课程可由多名学生来选修,每位教师只能讲授一门课程,每门课程只能由一位教师来讲授,那么该关系模式的主码是___。
A. 课程号
B. 教工号
C. 学号
D. 【学号,教工号】
【单选题】
下列关于关系模式规范化的叙述中,不正确的是___
A. 若R∈BCNF,则必然R∈3NF
B. 若R∈3NF,则必然R∈2NFC.
C. 若R∈2NF,则必然R∈INF
D. 若R∈INF,则必然R∈BCNF
【单选题】
下列关于E-R模型向关系模型转换的描述中,不正确的是___。
A. 一个实体类型转换成个关系模式,关系模式的码就是实体的码
B. 一个1 :n联系转换为一个关系模式,关系模式的码是1 : n联系的1端实体的码
C. 一个m: n联系转换为一一个关系模式,关系模式的码为各实体码的组合
D. 三个或三个以上实体间的多元联系转换为一个关系模式,关系模式的码为各实体码的组合
【单选题】
下列关于函数依赖的描述中,不正确的是___。
A. 若X→Y,Y→Z,则X→Z
B. 若X→Y, Y'属于Y,则X→Y'
C. 若X→Y, X'属于X,则X'→Y
D. 若X'属于X,则X →X'
【单选题】
关系数据库规范化中的删除异常是指___。
A. 应该删除的数据未被删除
B. 应该插入的数据未被插入
C. 不该被删除的数据被删除
D. 不该插入的数据被插入
【单选题】
假设有关系模式R(A.B,C,D,E),根据语义有如下函数依赖集F={A→C,【B,C】→D,【C,D】→A,【A,B】→E},则关系模式R的规范化程度最高达到___
I (A,B) II (A,D) III (B,C) IV (C,D) V (B,D)
A. 1NF
B. 2NF
C. 3NF
D. BCNF
【单选题】
假设有关系模式R(A.B,C,D,E),根据语义有如下函数依赖集F={A→C,【B,C】→D,【C,D】→A,【A,B】→E},则下列属性组中___是关系R的候选码。
I (A,B) II (A,D) III (B,C) IV (C,D) V (B,D)
A. 仅I I I
B. 仅I和I I I
C. 仅I、I I和I V
D. 仅I I 、I I I 和V
【单选题】
在将E-R模型向关系模型转换的过程中,若将三个实体之间的多元联系转换为一个关系模式,则该关系模式的码是___.
A. 其中任意两个实体的码的组合
B. 任意一个实体的码
C. 三个实体的码的组合
D. 三个实体中所有属性的组合
【单选题】
下列不是局部E-R模型集成为全局E-R模型时可能存在的冲突是()
A. 模型冲突
B. 结构冲突
C. 属性冲突
D. 命名冲突
【单选题】
数据库设计中,确定数据库存储结构,即确定关系、索引、聚簇、日志、备份等数据的储存安排和存储结构,这是数据库设计的___
A. 需求分析阶段
B. 逻辑设计阶段
C. 概念设计阶段
D. 物理设计阶段
【填空题】
1.数据库设计一般经过需求分析、___、___、___、数据库实施和数据库运行维护等6个阶段
【填空题】
2.对于非规范化的关系模式,经过___变为1NF,将1NF经过___变为2NF,将2NF经过___转变为3NF。
【填空题】
3.对于函数依赖X→Y,如果Y包含于X,则称X→Y是一个___
【填空题】
E-R模型是数据库的____阶段的一个有力工具,关系数据库规范化理论是数据库__阶段的一个有力工具
【填空题】
5.各分E-R模型之间的冲突主要有3类:___、___和___
【填空题】
6. X→Y是关系模式R的一个函教依赖,在当前值r的两个不同元组中,如果X值相同,就一定要求___。 也就是说,对于X的每个真体值,都有___与之对应。