相关试题
【单选题】
7二进制数11101转化成十进制数为___
【单选题】
8TTL系列集成芯片工作电源电压的典型值是___。
A. 18V
B. 5V
C. 3V
D. 10V
【单选题】
10以下表达式中符合逻辑运算法则的是___。
A. 1+1=10
B. A+A=2A
C. A+=1.
D. A·=1
【单选题】
11对于TTL与非门闲置输入端的处理，不可以___
A. 与有用输入端并联
B. 通过电阻3kΩ接电源
C. 接地
D. 接电源
【单选题】
12十线/四线优先编码器74LS147所用的输出代码为___。
A. 5421BCD码
B. 格雷码
C. 8421BCD码
D. 余3码
【单选题】
13为实现“线与”逻辑功能，应选用___
A. OC门
B. 与门
C. 异或门
D. 同或门
【单选题】
14和逻辑式A+ABC相等的式子是___
【单选题】
15逻辑函数的表示方法中具有唯一性的是___
A. 真值表
B. 表达式
C. 逻辑图
D. 卡诺图
【单选题】
16与模拟电路相比，数字电路主要的优点是___。
A. 容易设计
B. 通用性强
C. 抗干扰能力强
【单选题】
17某门电路的输入输出波形如图所示，试问此逻辑门的功能是___。
【单选题】
18以下电路中常用于总线应用的有___。
A. TSL门
B. OC门
C. 漏极开路门
D. CMOS与非门
【单选题】
逻辑表达式Y=AB可以用___实现。
A. 正或门
B. 正非门
C. 正与门
D. 负或门
【单选题】
20TTL电路在正逻辑系统中，以下各种输入中___相当于输入逻辑“0”。
A. 悬空
B. 通过电阻2.7kΩ接电源
C. 通过电阻2.7kΩ接地
D. 通过电阻510Ω接地
【单选题】
21对于TTL与非门闲置输入端的处理，不可以___。
A. 接电源
B. 通过电阻3kΩ接电源
C. 接地
D. 与有用输入端并联
【单选题】
22STTL数字集成电路与CMO数字集成电路相比突出的优点是___。
A. 微功耗
B. 高速度
C. 高抗干扰能力
D. 电源范围宽
【单选题】
23以下式子中正确的是___
A. 1+A＝A
B. A＋A=1
C. A•A＝1
D. A+AB=A
【单选题】
在一个四变量逻辑函数中，___为最小项。
【单选题】
A+BC=___。
A. A+B
B. A+C
C. （A+B）（A+C）
D. B+C
【单选题】
26以下代码中为无权码的为___。
A. 5421BCD码
B. 8421BCD码
C. 余三码
【单选题】
一位十六进制数可以用___位二进制数来表示。
【单选题】
28十进制数25用8421BCD码表示为___。4位
A. 10 101
B. 0010 0101
C. 100101
D. 10101
【单选题】
29与十进制数（53.5）10不等值的数或代码为___。
A. (0101 0011.0101)8421BCD
B. (35.8)16
C. (110101.1)2
D. (60.4)8
【单选题】
30与八进制数(47.3)8等值的数为___
A. (100111.011)2
B. (97.3)16
C. (27.3 )16
D. (100111.11)2
【单选题】
31下列各型号中属于优先编码器是___。
A. 74LS85
B. 74LS138
C. 74LS148
D. 74LS48
【单选题】
七段数码显示器BS202是___。
A. 共阳极LED管
B. 共阴极LED管
C. 共阳极LCD管
D. 共阴极LCD管
【单选题】
33八输入端的编码器按二进制数编码时，其输出端的个数是___。
【单选题】
四输入的译码器，其输出端最多为___。
A. 4个
B. 8个
C. 10个
D. 16个
【单选题】
当74LS148的输入端按顺序输入11011101时，输出为___。
A. 101
B. 010
C. 001
D. 110
【单选题】
用三线-八线译码器74LS138和辅助门电路实现逻辑函数Y=a2+a1a2，应___。
A. 用与非门，Y=y0y1y4y5y6y7
B. 用与门，Y=y2y3
C. 用或门，Y=y2+y3
D. 用或门，Y=y0+y1+y4+y5+y6+y7
【单选题】
37时序逻辑电路中一定包含___。
A. 触发器
B. 组合逻辑电路
C. 移位寄存器
D. 译码器
【单选题】
仅具有置“0”和置“1”功能的触发器是___。
A. 基本RS触发器
B. 钟控RS触发器
C. D触发器
D. JK触发器
【单选题】
由与非门组成的基本RS触发器不允许输入的变量组合为___。
【单选题】
40仅具有保持和翻转功能的触发器是___。
A. JK触发器
B. T触发器
C. D触发器
D. T' 触发器
【单选题】
触发器由门电路构成，但它不同于门电路功能，主要特点是___。
A. 具有翻转功能
B. 具有保持功能
C. 具有记忆功能
【单选题】
TTL集成触发器直接置0端[]和直接置1端[]在触发器正常工作时应___。
A. =1，=0
B. =0，=1
C. 保持高电平“1”
D. 保持低电平“0”
【单选题】
按逻辑功能的不同，双稳态触发器可分为___。
A. RS、JK、D、T等
B. 主从型和维持阻塞型
C. TTL型和MOS型
D. 上述均包括
【单选题】
同步计数器和异步计数器比较，同步计数器的显著优点是___。
A. 工作速度高
B. 触发器利用率高
C. 电路简单
D. 不受时钟CP控制。
【单选题】
把一个五进制计数器与一个四进制计数器串联可得到___进制计数器。
【单选题】
下列逻辑电路中为时序逻辑电路的是___ 。
A. 变量译码器
B. 加法器
C. 数码寄存器
D. 数据选择器
推荐试题
【单选题】
中国共产党要把______这场伟大的革命进行好，党必须进行自我革命，全面增强党的执政本领。 ___
A. 新时代经济体制改革
B. 新时代政治体制改革
C. 新时代坚持和发展中国特色社会主义
D. 新时代中国改革开放
【单选题】
中国特色社会主义道路是实现社会主义现代化、创造人民美好生活的______。___
A. 理论依据
B. 必由之路
C. 根本保障
D. 行动指南
【单选题】
确保党始终总揽全局、协调各方，必须____。___
A. 得民心者得天下
B. 坚持和完善党的领导的体制机制
C. 学习达国家的经验
D. 选举优秀领导人
【单选题】
增强面对新时代新使命,必须在全党营造善于学习、勇于实践的浓厚氛围，建设马克思主义____政党。 ___
A. 人民型
B. 事业型
C. 研究型
D. 学习型
【单选题】
必须坚持党的（ ），既要充分发扬民主，又要善于集中。 ___
A. 集中民主制
B. 民主集中制
C. 多党合作制
D. 全民民主制
【单选题】
党是最高政治领导力量，是推进伟大事业的（ ）保证。 ___
【单选题】
According to one study, what do green spaces do to people? ___
A. Improve their work efficiently.
B. Add to their sustained happiness.
C. Help them build a positive attitude towards life.
D. Lessen their concerns about material well-being.
【单选题】
What does Dr. White say people usually do to make themselves happier? ___
A. Earn more money.
B. Settle in an urban area.
C. Gain fame and popularity.
D. Live in a green environment.
【单选题】
What does Dr. White try to find out about living in a greener urban area? ___
A. How it affects different people.
B. How strong its positive effect is.
C. How long its positive effect lasts.
D. How it benefits people physically.
【单选题】
What did Dr. White’s research reveal about people living in a green environment? ___
A. Their stress was more apparent than real.
B. Their decisions required less deliberation.
C. Their memories were greatly strengthened.
D. Their communication with others improved.
【单选题】
According to Dr. White, what should the government do to build more green spaces in cities? ___
A. Find financial support.
B. Improve urban planning.
C. Involve local residents in the effort.
D. Raise public awareness of the issue.
【单选题】
The survey by the Kaiser Family Foundation is mentioned to illustrate the idea that . ___
A. kids don’t always follow parents’ rules
B. only few parents believe the good news
C. much media use results in bad health
D. parents’ rules make a huge difference
【单选题】
What did the kids do when parents set any time or content limits, according to the Kaiser Family Foundation? ___
A. They cut down on their screen time.
B. They appreciated their parents’ love.
C. They spent more time staying outdoor.
D. They accepted parents’ rules unwillingly.
【单选题】
What will Kenneth Ginsburg most probably suggest that parents should do? ___
A. Avoid setting firm rules.
B. Avoid ruling with an iron grip.
C. Set rules after family discussion.
D. Set rules that are easy to understand.
【单选题】
Margaret Broe -Fitzpatrick finds it impossible. ___
A. to achieve just- right parenting
B. to keep track of everything done by the kids
C. for the kids to face rules alone
D. for the kids to observe rules without protest
【单选题】
The passage is mainly intended for parents . ___
A. whose kids have difficulty in self- discipline
B. whose kids are addicted to media use
C. who have doubts about setting rules
D. who are too busy to care for their kids
【单选题】
The word “it” (Para. 2) most probably refers to. ___
A. the lack of stable communities
B. the breakdown of informal information channels
C. the increased mobility of families
D. the growing number of people moving from place to place
【单选题】
The main problem people may encounter today arises from the fact that . ___
A. they have to learn new things consciously
B. they lack the confidence of securing reliable and trustworthy information
C. they have difficulty obtaining the needed information readily
D. they can hardly carry out casual communications with an extended family
【单选题】
From the passage we can infer that _______. ___
A. electronic mail will soon play a dominant role in transmitting messages
B. it will become more difficult for people to keep secrets in an information era
C. people will spend less time holding meetings or conferences
D. events will be reported on the spot mainly through satellites
【单选题】
Technology facilitates _______. ___
A. sharing information
B. storing and sending information
C. providing people with easy access to more information
D. all of the above
【单选题】
We can learn from the last paragraph that _______. ___
A. it is necessary to obtain as much
B. people should make the best use of the information
C. we should realize the importance of accumulating information
D. it is of vital importance to acquire needed information efficiently
【单选题】
The author thinks that people are _________. ___
A. satisfied with their appearance
B. concerned about appearance in old age
C. far from neglecting what is in fashion
D. reluctant to follow the trends in fashion
【单选题】
Fashion magazines and TV advertisements seem to link fashion to _________. ___
A. confidence in life
B. personal dress
C. individual hair style
D. personal future
【单选题】
Causes of fashions are _________. ___
A. uniform
B. varied
C. unknown
D. inexplicable
【单选题】
Present-day society is much freer and easier because it emphasizes _________. ___
A. uniformity
B. formality
C. informality
D. individuality
【单选题】
Which is the main idea of the last paragraph? ______________ ___
A. Care about appearance in formal situations.
B. Fashion in formal and informal situations.
C. Ignoring appearance in informal situations.
D. Ignoring appearance in all situations.
【单选题】
Permissive parents would ________. ___
A. let their children read any books they like to
B. not let their children see any films they like to
C. not let their children read any books without first checking their contents
D. let their children see the films with their first checking
【单选题】
The fact that parents check the contents of the book or the film for their children to read or see shows __________. ___
A. the necessity of censorship
B. that many books and films are bad
C. that children need their parents to help them understand more
D. that the parents are permissive
【单选题】
Which of the following statements is NOT true?____________ ___
A. Some adults can’t tell right from wrong.
B. Censorship is compared to the law because both of them perform good service to society as a whole.
C. Censors pay attention only to genuine works of art.
D. Censorship is necessary because many books, plays and films are far from being “works of art”.
【单选题】
What does the word “corrupt” in Para.4 mean?__________ ___
A. Make morally bad.
B. Hurt.
C. Injure.
D. Damage.
【单选题】
What would be the best title of this passage?_____________ ___
A. Permissive Parents and Responsible Parents.
B. Censorship and the Law.
C. Censors Value Artistic Merits .
D. Censorship Performs Good Service to Society.
【单选题】
Lie detectors are widely used in the United States because _____________. ___
A. they can help detect people’s emotional stress
B. they can help detect people's physiological changes
C. they can help find out whether a person is telling the truth or not
D. they can measure the subject’s electrical resistance
【单选题】
According to the passage, we know that Britain______________. ___
A. will adopt lie detectors widely
B. will adopt lie detectors on a smaller scale
C. adopt lie detectors
D. has not decided whether to adopt lie detectors or not
【单选题】
The tests themselves are by no means free from error..." (Line 1-2.Para.3) means ____________. ___
A. the tests definitely have no error
B. the tests sometimes make mistakes
C. the polygraphers do not make mistakes
D. the polygraphers can avoid error by using some techniques
【单选题】
Which of the following is true? ________________ ___
A. The tests are conducted by qualified polygraphers.
B. Innocent people may blush or stammer when questioned.
C. Guilty people can definitely be found out by answer questions
D. Guilty people may escape by refusing to answer questions.
【单选题】
What troubles lie detector researchers most is that _______________. ___
A. innocent people are convicted crimes
B. innocent people will learn to tell lies
C. lie detectors may cause industrial unrests
D. lie detectors are sometimes not dependable
【单选题】
In the passage the author's attitude towards "mixed-ability teaching" is _______. ___
A. critical
B. questioning
C. approving
D. objective
【单选题】
By "held back" (Line 1) the author means _____. ___
A. made to remain in the same classes
B. forced to study in the lower classes
C. drawn to their studies
D. prevented from advancing
【单选题】
The author argues that a teacher's chief concern should be the development of the student's _________. ___
A. personal qualities and social skills
B. total personality
C. learning ability and communicative skills
D. intellectual ability
【单选题】
Which of the following is NOT MENTIONED in the third paragraph? __________ ___
A. Group work gives pupils the opportunity to learn to work together with others.
B. Pupils also learn to develop their reasoning abilities.
C. Group work provides pupils with the opportunity to learn to be capable organizers.
D. Pupils also learn how to participate in teaching activities.
