测量上确定点的位置是通过测定三个定位元素来实现的,下面哪个不在其中( )。
大地水准面包围的地球形体,称为( )。
通过平均海水面并延伸穿过陆地所形成的闭合曲面称为( )。
某点的经度为东经123°30′,该点位于高斯平面投影6°带的第( )带号。
以子午线投影为纵轴,赤道投影为横轴建立的坐标系是( )。
设a点的通用坐标为(38246.78,19525833.20)米,则该点所在6度带带号及其坐标自然值为( )。
地面点沿( )至大地水准面的距离称为该点的绝对高程。
测量中所用的平面直角坐标系与数学中所用的不同,应用数学中的三角公式计算坐标时( )。
高斯平面直角坐标系横轴为y。
高斯正形投影中,离子午线越远,子午线长度变形越大。
水准原点是全国高程的起点,它的绝对高程为零。
大地水准面是一个不规则的封闭曲面,大地水准面上各点的高程相等。
测量三要素是指对中、整平、定向。
已知点p的统一坐标为(2050442.5,19523775.2),则该点位于高斯投影6度带中的第 带内。
ab两点之间的高差为hab=-0.123m,则说明 点高。
水准测量是利用水准仪提供的( )来测定两点间高差的。
水准测量中,后视点a的高程为40.000m,后视读数为1.125m,前视读数为2.571m,则前视点b的高程应为( )。
中心十字丝交点与物镜中心的连线称为望远镜的( )。
水准测量中,调节圆水准气泡居中的目的是使( )。
水准测量中,立尺点分别为水准点和转点两类,在使用尺垫时( )。
水准测量中,前后视距相等不可以消除或消弱( )。
采用前后视距相等,可以消除以下( )误差
下面属于高程测量的方法有( )
高程测量就是利用水平视线来求得两点之间的高差,继而根据已知点高程推算出另一点的高程。
水准尺没有扶直,无论向哪一侧倾斜都使读数偏大。
水准仪的视准轴是十字丝中心与物镜光心的连线.
高差hab < 0,表明待求点b高于已知点
视差产生的原因在于目标影像没有与十字丝分划板重合。
水准测量中,a尺读数为1.234m,b尺读数为0.500m,则 hba= m。
水准测量中,设后尺a的读数a=2.713m,前尺b的读数为b=1.401m,已知a点高程为15.000m,则视线高程为 m
水平角测量中,( )误差不能用盘左盘右观测取平均值的方法消除。
用经纬仪观测水平角时,尽量照准目标的底部,其主要目的是为了消除( )误差对测角的影响。
水平角测量中,哪项误差不能用盘左盘右取平均值的观测方法消除( )
采用测回法观测水平角,盘左和盘右瞄准同一方向的水平度盘读数,理论上应( )。
测回法观测水平角,若右方目标的方向值a小于左方目标的方向值b时,水平角β的计算方法是( )
视准轴指的是( )。
用回测法观测水平角,测完上半测回后,发现水准管气泡偏离2格多,在此情况下应( )。 a.继续观测下半测回; b.整平后观测下半测回; c.整平后全部重测
下列说确的是( )
采用测回法观测水平角,盘左和盘右瞄准同一方向的水平度盘读数,理论上应相差90度
角度测量照准目标时应尽量瞄准地面目标的顶部。
全站仪的整平(包括粗平和精平)是通过旋转脚螺旋来实现的。
在进行水平角观测时,不考虑仪器误差,若瞄准的是目标正上方的某点,则所测的角度与该角的实际值相同。
全站仪对中的目的是仪器中心与测站点在一条铅垂线上。
1、用6秒级测角仪器,测回法测量,得下表水平角β观测值,试完成表中的各项计算。
下列哪一项实验属于整体水平的研究( )
刚能引起组织发生反应的最小强度称为( )
维持机体稳态的重要调节过程是( )
神经调节的基本方式是( )
机体对内、外环境变化发生反应的能力称为(
生理学研究中,最常用的方法是
轻触眼球角膜引起眨眼中作的调节属于( )
通常生理学的研究方法分为三个水平,即
机体对产生反应的形式有两种,即
人体细胞直接生活的环境称为
神经调节的基本方式是
完成神经调节的结构基础是
入体的可兴奋组织有三种,即
什么是生命活动
骨骼肌兴奋—收缩耦联中起关键作用的离子是:
骨骼肌收缩和舒张的基本功能单位是
神经-肌肉接头的处的化学递质是
骨骼的作用有哪些
肌肉酸痛的主要类型
神经与肌肉之间的兴奋性神经递质是肾上腺素
终板电位是动作电位
肌肉收缩时,肌节的缩短是因为肌微丝本身的长度缩短所致
骨骼肌的兴奋性显著高于心肌和平滑肌。
简述骨骼肌的兴奋收缩耦联过程
通常所说的血型是指
一个体重为60kg的人,其血量约为
构成血浆胶体渗透压的主要成分是
若将红细胞置于o.35%的nacl溶液中,将会出现如下哪种现象
正常人的小血管受损时,自行止血是通过以下哪些实现的
下列哪些情况可延缓或防止凝血
人体血浆清蛋白
每毫升血液中数量是最多的血细胞是红细胞。
低温可加速血液凝固。
血液加温可加速血液凝固
血小板数量减少时动物血凝减慢
白细胞对机体有保护作用
哺乳动物成熟的红细胞没有细胞核
血量维持相对稳定是生命活动所必需的,因此血量的轻微变化就会导致严重的身体不适。
机体剧烈运动和处于缺氧环境时,血液红细胞数目有何改变?原因是什么?
下关于心动周期的论述,哪项是错误的
在心动周期中,占时间最长的是
心动周期中,心室的血液充盈主要取决于
在一次心动周期中,室内压升高速度最快的是
主动脉瓣关闭发生在
在心动周期中,房室瓣关闭至房室瓣开放的时程相当于
正常人心率超过180次/分时,引起心输出量减少的主要原因是:
心动周期中
心室每搏输出量的多少取决于
心肌的工作细胞具有
决定和影响心肌兴奋性的因素包括0期自动去极化速度和幅度
心室收缩期 中,心室肌对外来不发生反应
慢反应细胞的特点包括兴奋性低,自律性低
等容收缩期之末刚好是主动脉血压最低
每个心动周期由心房收缩挤入心室的血量可使心室的充盈量再增加10%~15%
在一个心动周期中,心房和心室是怎样活动的?为什么说心率加快对心脏不利?
在下列哪个平面横断脑干后仍能保持正常呼吸节律
动脉血h 浓度增高兴奋呼吸的作用主要不是通过中枢化学感受器而实现的,其原因是
实现肺通气的组织器官是
中枢化学感受器最敏感的物是
肺通气时构成非弹性阻力的主要成分
维持胸内负压的必要条件是
列哪项能引起呼吸道口径增大
影响肺泡气体交换的因素有
二氧化碳在血液中的运输方式有
肺牵张反射的作用是抑制吸气中枢
控制呼吸的基本中枢位于脊髓。
肺泡表面张力可因表面活性物质的作用而减少
肺换气是指肺泡与血液之间的气体交换。
增加呼吸道的容积意味着解剖无效腔增大
血红蛋白的氧容量是指血浆中溶解的氧的毫升数
影响呼吸器官内气体交换的因素
对脂肪和蛋白质的消化,作用最强的消化液是
关于唾液的生理作用,哪一项叙述是错误的
关于胃酸的生理作用的叙述,哪一项是错误的
参与脂肪消化分解的消化液是
能水解蛋白质的消化液是
胃最具生理意义的运动是
胃肠道激素多数产生于
胃的运动功能有
胃肠激素的生理作用有
消化道平滑肌的生理特征有
抑制胃酸分泌的因素有
经过化学性消化,食物中的大分子物质转变为可吸收的小分子物质。
消化道平滑肌的动作电位主要是na 内流形成的
慢波是消化道平滑肌收缩节律的控制波,并决定蠕动的方向、节律和速率。
抑胃肽有很强的抑制胰岛素分泌的作用。
口服葡萄糖与静脉注射同样剂量的葡萄糖相比,口服葡萄糖能引起更多的胰岛素分泌。
消化管的肌肉全部由平滑肌组成。
消化道平滑肌的生理特性
动物机体最主要的排泄器官是
分泌肾素的部位是
一般情况下,维持肾血流量的相对稳定主要依靠
肾的致密斑是
原尿与血浆的主要区别是
导致肾小球滤过率改变的因素是
肾小球滤过率是指每分钟
引起渗透性利尿的原因是
肾素
抗利尿激素分泌增多可
管不属于肾单位的结构
由大肠排出食物残渣也属于生理排泄物
肾小球滤过率是决定终尿量的主要因素。
在正常情况下,肾小球滤过率与动脉血压、滤过膜的通透性及滤过面积成正变关系。
近曲小管对水重吸收量很大,因此对终尿的调节作用也很大。
部分肾小管对葡萄糖的重吸收已达到极限时尿中一般不会出现葡萄糖。
简述肾的生理机能
调节机体各种功能活动的两大信息传递系统是
主要通过细胞膜受体起作用的激素是:
“旁分泌”就是:
在下列器官或组织中,能产生激素的有
甲状腺功能减退时可能出现哪些表现
盐皮质激素对细胞外液中哪些物质有较强的调节作用:
垂体后叶激素是加压素与催产素
下丘脑室旁核主要分泌生长激素
呆小症是由于甲状腺激素不足
简述地方性甲状腺肿的发病机制和原因
切除肾上腺引起动物死亡的原因,主要是由于缺乏
调节胰岛素分泌最重要的因素是
降钙素的主要靶器官是
影响神经系统发育的最重要的激素是
关于内分泌系统的最佳描述是
下丘脑调节腺垂体分泌促甲状腺素的因子有
生长素
引起血糖升高的激素有
加压素的主要生理作用是促进肾对排钾保钠作用
生长激素不是含氮激素
男性的主要生殖器官为
形成睾酮的原料是:
关于雄激素的作用的叙述,下列哪项是错误的?
切除睾丸后,血中fsh的浓度增加是由于
附睾是
睾酮的生理作用有
体内哪些部位可以产生雌激素
排卵后基础体温减少0.5℃左右
进入青春期后,身高的迅速升高,称青春期突长
睾丸具有产生和内分泌的双重功能
什么是初乳
消化道平滑肌慢波起源于
能水解淀粉的消化液是
致密斑的主要功能是
胆盐的肠肝循环可以促进
人在寒冷环境中,主要依靠哪种方式增加产热量
盐酸进入小肠后的直接作用
内因子的作用是
黄体退化、萎缩是由于
肺总容量等于
重吸收葡萄糖的部位是
能促进机体产热的最重要的激素是
酒精擦浴降温主要是增加了皮肤的
决定肺部气体交换方向的主要因素是
由于h -na 交换与k -na 交换之间有竞争性抑制作用,所以酸中毒时可导致高钾血症
睾丸是雄性动物合成和分泌雄性激素的唯一器官。
前列腺素由前列腺产生,其种类很多,作用也相当广泛。
co中毒所引起的缺氧比贫血引起的同等程度hb减少所致的缺氧更为严重,这是因为血氧含量降低。
由于通气/血流比值异常,导致肺泡与血液间气体交换不充分时,主要表现为缺o2明显,co2潴留不明显。
除内分泌腺外,体内尚有很多细胞能分泌激素。
抗利尿激素是由神经垂体释放的。
慢波是消化道平滑肌收缩节律的控制波,并决定蠕动的方向、节律和速率。
正常情况下,肺泡气po2发生较大变化时,组织po2只发生很小变化,这主要是因为hb具有氧缓冲机能。
lh的靶细胞之一是睾丸间质细胞,能睾酮的合成。
下列不属于《高层建筑混凝土结构技术规程》所规定的高层建筑的是
下列不属于《高层建筑混凝土结构技术规程》所规定的高层建筑的是
关于框架结构、剪力墙结构、框架-剪力墙结构侧向位移表述正确的是
框架-剪力墙结构在侧向荷载作用下的侧向位移为
以下不属于《高层建筑混凝土结构技术规程》规定的高层建筑的是
在常用的钢筋混凝土高层建筑结构体系中,抗侧刚度最好的结构体系是
框架结构与剪力墙结构相比,下列所述哪种是正确的?
高层建筑结构防震缝的设置,下列所述哪种是正确的?
关于《高层建筑混凝土结构技术规程》中房屋高度的取值,下列说确的是
下列结构体系中抗震性能最差的是
下列关于框架结构和剪力墙结构侧向变形描述正确的是
下列不属于常用的钢筋混凝土高层建筑竖向结构体系的是
简述剪力墙结构的优缺点和适用范围。
使建筑结构产生竖向刚度突变的原因是什么?
结构规则性判断
不属于框架结构柱网布置时需满足的要求的是
框架结构的整体变形主要呈现为
框架结构内力计算的弯矩调幅
下列不属于竖向活荷载最不利布置的方法是
对现浇楼盖,在计算框架梁截面惯性矩时应考虑楼板的影响,下列说法错误的是
下列关于框架结构计算简图表述错误的是
当永久荷载效应对结构有利时,其荷载分项系数一般取下列哪一数值?
按分层法或弯矩分配法求得框架梁端支座弯矩后,梁跨中弯矩求解时的荷载取值为
下列关于梁端弯矩调幅考虑,说法错误的是
关于框架结构内力计算的反弯点法,下列说法错误的是
关于多层框架结构而言,下列说法错误的是
关于框架结构的变形,哪个结论是正确的?
框架结构在竖向荷载作用下,可以考虑梁塑性内力重分布而对梁端负弯矩进行调幅,下列哪种调幅及组合方法是正确的?
关于框架柱的反弯点,哪个结论是正确的?
以下关于框架的观点,哪个是正确的?
下列关于框架结构计算简图描述错误的是
下列关于竖向荷载作用下分层法计算,说法错误的是
下列关于框架结构计算简图描述正确的是
下列关于竖向荷载作用下分层法计算正确的是
下列关于框架结构弯矩调幅的说法,错误的是
关于d值法,下列描述正确的是
下列关于框架结构计算方法的表述错误的是
关于框架结构弯矩调幅,下列表述错误的是
下列关于框架结构在水平荷载作用下柱反弯点的表述错误的是
下列关于反弯点法表述错误的是
下列关于框架结构计算方法的表述正确的是
下列关于反弯点法表述正确的是
下列不属于梁端弯矩调幅考虑因素的是
水平荷载作用下的多层框架结构,当某层其他条件不变,仅上层层高变小时,该层柱的反弯点位置
五等跨连续梁,为使第三跨跨中出现最小正弯矩,活荷载应布置在
框架结构按施工方法可分为哪几类?说明框架结构柱网布置的要求。
在用d值法进行水平荷载作用下框架结构的内力计算时,柱反弯点高度在反弯点法基础上的修正需考虑的影响因素有哪些?
简述反弯点法的计算假定。
简述在水平荷载作用下影响框架柱两端转角大小的因素。
简述分层法的计算假定。
there are two major sharing-bike companies in daxuecheng.
according to tommy, mobike originally focuses on the white-collar crowd.
none of the students interviewed recognized environmental contribution of sharing bike.
what does the author think can help a bank to recover from financial crisis?
what effect will climate change have?
what does the author think of the relationship between economy and nature?
what does the rainforests project aim to do?
how could rainforest nations achieve sustainable development?
students have got into the spirit, waging competitions to boost recycling and slash energy use in dorms.
they cut discarded books from bindings so the paper could be recycled.
green buildings are also cropping up on campuses, from duke with its green-roofed “smart home” to the new university of california, merced.
yet even when the basic science of climate change has been accepted by almost all scientists, many others still seem to think that it is unfounded.
this is precisely why my rainforests project has expended so much effort during these last two years to help facilitate a consensus on increasing international cooperation to cut deforestation.
if in the future it becomes clear that the world’s big polluters knew but did little or nothing about these problems, a whole new generation of resentment might be born.
the presidential candidates all tout green-collar jobs like mcanally’s as part of their plans to combat climate change.
“i can’t say for sure what kind of steak it is,” the waitress solemnly answered, “but i can assure you it was raised in a stress-free environment.”
several studies have set out how climate change will threaten economic development, especially in the most vulnerable and poorest countries.
by using innovative, long-term investment instruments, perhaps facilitated by the multilateral development banks, we could restore vast areas of already degraded land to increase food output.
cornell president believes that students have taken great initiative in earth-protecting movement.
a very famous university kalamazoo college in michigan won the nationwide recyclemania competition in 2008.
the typical feature of a green building is recyclable, reusable.
the universities offer courses and scholarships to encourage students to study the environment.
the ultimate goal of students’ doing research projects on the environment is to cultivate environmental scientists.
the environmental historian jeremy vetter believes “humans have transformed the environment, and the environment has affected human events.” please use you own words to explain how you understand the words of jeremy within 150 to 200 words, evidences or data are welcomed.
the student feels upset because he failed in job interview several times.
gloria failed in the interviews because she didn’t prepare well.
jordan suggests that an outline for answers would be better than writing them all out.
besides in job interview, gloria also has difficulty in study in school.
who released the report college learning for the new global century?
what type of employees do business executives find a shortage of?
what’s the negative side the previous report had?
what’s the key to continued success in the workforce according to business leaders and recent graduates?
what type of graduate will become a good investment for an employer?
what can we know about the report according to the passage?
read the passage global competence: the knowledge and skills our students need, and decide whether the following statements are true or false according to the passage. write t or f in the brackets. whatever people do in their daily life is closely connected to the world beyond their borders.
the questions globally competent students ask and explore can make them fully involved in investigating the world.
globally competent students are able to yze the questions critically and provide right answers.
both historical knowledge and contemporary events can help people shape their perspectives.
english is the only world language globally competent students can use to communicate with erse audiences effectively.
globally competent students are good at adapting themselves to culturally erse settings and working effectively with the team.
globally competent students are quick to take actions regardless of the consequences.
an interdisciplinary study can help students more specialized in their own field.
we need to recognize that a 21st century education is the bedrock of competitiveness — the engine, not simply an input, of the economy.
job skills can also be called transferable skills, since they are the type of aptitudes you acquire through work experience.
our age demands workers to be able to synthesize different types of information creatively.
to survive in this ever-flattening world, iniduals must ersify their skills so that they remain viable compes across many different careers.
economists believe jobs that require higher-order thinking, judgment, and communication skills are relatively immune to the competitive job market.
proficiency in reading, writing, and arithmetic has traditionally been the entry-level threshold to the job market, but the new workplace requires more from its employees.
those growing up in the world of today — and tomorrow — need preparation to tackle the range of pervasive problems such as human conflict, climate change.
today, the vast majority of teaching around the world is still geared to preparing young people for lives in the 20th centuries.
global education is thought to encompass education for human rights, sustainability, peace and conflict prevention, interculturality, and citizenship.
narrow job skills that most employees learn today will be obsolete within three to five years.
xiao wang is worrying about to find a job at a foreign company.
overdressed is better than underdressed when the attire is unclear in the company.
xiao wang was suggested to inform her boss whenever she was in struggle with a dilemma.
no-work related activities should be avoided in the company.
there is no word in english for working yourself to death, because____.
who work the longest time in the world?
what does prof cooper think of “working arter”?
according to derek simpson, one’s stress is mainly caused by____.
what is the result of long-hours culture in uk?
it is implied that compared with other european people, british people____.
for how many hours a week do british full-time workers work?
the lawyer is an energetic, assertive and tricky man, always ready to find out a lot of beneficial evidence, argue with his counter-lawyers, and set a trap to win the case for his party.
that nice young man is an introvert man with a wife who is bossy, talkative and self-will, but sociable with his friends.
as a good employer, i need to have a good attitude towards my job, do the best possible in my position, and finally yet importantly restrain myself from discoursing my company’s secrets.
the businessperson is a person of the highest integrity, who is loyal to his customers, tough to any illegal and evil trade, fair to handle any business, and will try his best to protect the justice, transparency and freedom of the trade.
as an innovative leader, one has to own the accountability to improve himself and his staff's ability to adapt to the new and ever-changing market.
they have little incentive to go out and make loans to job-creating businesses that might have a higher yield but entail significant risk and effort.
if you receive notice that you are facing a discrimination complaint, your first inclination may be to react instantaneously to make the problem go away.
when nature delivers a major disaster with extended power failures and destruction, neighborhood areas can become isolated and inaccessible to first responders and local authorities.
inflation is the most often cited flaw in discussions about india’s economy, but the central bank there knows how to raise rates without sending investors running for cover.
creating an environment where people enjoy and value their work is key. to do this 1) ________, leaders must be sure to communicate clear expectations for every member of the organization. these expectations should be supported by the words and actions of managers who let people know how their work is important to the organization. iniduals should be given 2) _______ that are consistent with their strengths and interests, and opportunities for need learning and growth should be provided the importance of understanding organizational culture cannot be 3) _______. the bottom line for managers who want to create a culture of success is to start with creating a positive environment. bring in people whose values are in 4) ______ with the organization’s culture, and continue to acknowledge success and involve the whole organization in 5)______ an environment that allows people to enjoy working hard to meet the company’s goals. 1)______
2)______
3)______
4)______
5)______
choose the best answer for the following questions based on what you’ve read in the passage of why does corporate culture matter. which statement is true about a corporate culture?
what are the trained employees supposed to do when customers ask them questions?
if a company values teamwork, __________.
what do the executives and employees of this company believe?
what can be inferred from the passage?
the movie explores what a dog would like to do.
the movie “a dog’s purpose” tries to find the meaning of life through several lives of a dog.
the story of the movie teach us to love dogs.
what made jane goodall famous around the world?
what is the mission of the jane goodall institute?
what makes jane goodall an environmental activist?
why does jane goodall try to raise environmental awareness of people in developed countries?
what is most important for protecting animals and the environment?
what does jane goodall tell people to do first to protect animals and the environment?
during shakespear’s time, people used to take pet animals as family members, so those who advocated ban of animal cruelty would be called insane.
animal rights had been a wild notion, which was laughed at by the public.
thanks to his support, otherwise, it would be impossible that i could withstand the pressure from the authority.
this book is inspiring, reminding readers how much people have accepted the philosophy of humani.
if we’d all work together, i think we could accomplish our goal.
politeness and truth are often mutually incompatible.
the warning signs of the disease are so subtle that they are often ignored.
with the passage of the animal rights act, we realized that the rescued dogs, cats, rabbits and horses who live with so many of us today ultimately owe their survival to it.
read the passage when we abuse animals we debase ourselves, and decide whether the following statements are true or false. they public were shocked at the video on animal abuse.
human beings growing richer in moral qualities contributes to the survival of animals.
animals are proved amoral and immune to pain.
we learned from elephant the compatibility of power and gentleness.
the “golden rule” of conduct toward all species is to treat animals with the utmost dignity and respect.
please summarize the passage when we abuse animals we debase ourselves with the help of the following map.
1.儿童保健的目的?
2.假设您是一位父亲或者母亲,怎样根据不同年龄阶段对孩子进行健康促进?(选择2个年龄段说明)
如何利用体格评价监测儿童的生长情况?
请你谈一下对儿童生长发育影响因素的看法?
下列( )那些运算符都是可交换的
设p:2×2=5,q:雪是黑的,r:2×4=8,s:太阳从东方升起,下列( )命题的真值为真。
全体小项合取式为( )。
下列哪些公式为永真蕴含式( )。
令p:今天下雪了,q:路滑,则命题“虽然今天下雪了,但是路不滑”可符号化为
对一阶逻辑公式的说确的是( )。
设个体域为有理数集q,则以下谓词公式中为假的是()。
“人总是要死的”谓词公式表示为( )。 (论域为全总个体域)m(x):x是人;mortal(x):x是要死的。
设b不含有x,下列一阶逻辑等值式不正确的是
下列是命题公式p∧(q∨┓r)的成真赋值的是( )
下列语句是命题的有( )。
若和b为wff,且则( )。
命题“存在一些人是大学生”的否定是:“所有人都不是大学生”
一个命题公式的主合取范式或主析取范式是唯一的.
不是最小联结词组
能够判断真假的陈述句称为________。
命题公式的真值为 。
中r(x,y)中的y为________。
将量词辖域中出现的 和指导变元交换为另一变元符号,公式其余的部分不变,这种方法称为换名规则。
公式化简为___________。
命题公式a中含有n个命题变元,其主析取范式中含有 k个小项,则其主合取范式中含有 个大项
下列语句哪个是真命题? (
是( )
下面哪组命题公式是等价的( )
下列联结词中,哪个是最小联结词组( )
下列命题公式为永真式的是( )
设p:他聪明,q:他成绩好,则命题“他虽聪明但成绩不好”可表示为( ).
2个命题变元可构成 个不等价的命题公式.
的对偶式是( )
使命题公式真值为真的指派有( )个
设是命题公式,则
谓词公式中,量词的辖域是( )。
谓词公式中的变元x是 ( )
下面谓词公式哪个是前束范式( )
对于谓词公式,约束变元换名正确的是( )
下列式子不是谓词合式公式的是( ).
对于公式,下列说确的是( ).
设b是不含变元x的公式,谓词公式等价于( )
设a(x):x是实数,b(x):x是有理数,则命题“有的实数是有理数”符号化为( )
下列等价式错误的是( )
下列等价式正确的是( )
设s={,{1},{1,2}},则有( )s。
设s={1,2,3},s上关系r的关系图为,则r具有( )性质。
设a={1 ,2 ,3},则a上有( )个二元关系。
下列关系中能构成函数的是( )。
设a={1,2,3,4,5}上偏序关系的哈斯图为, 则子集b={2,3,4}的最大元( );最小元( );极大元( );极小元( );上界( );上确界( );下界( );下确界( )。
设a={a,b,c},a上的等价关系r所确定的a的划分是{{a},{b,c}},则r=( ) .
设 a={x|{xn)且(x<5)},b={x|xe 且x<7}(n:自然数集,e 正偶数) 则ab= 。
设a={a,b,c},a上二元关系r={< a, a > , < a, b >,< a, c >, < c, c>} , 则s(r)= 。
设a={1,2,3,4},a上关系图为, 则 r2 = 。
设 f,g是自然数集n上的函数xn,f(x)=x 1,g(x)=2x,则fg(x)=______。
设a={1,2,¼,1000}, a 上关系 r={(x,y)| x,y îa,且 x y=1000}, 则 r满足的性质是( ).
a的一个划分,确定了a的元素间关系为( ).
设 a={1,2,3},a上的关系r={<1,1>, <1,2>, <2,2>, <3,3>, <3,2>},则r不具备( ) 。
设a={{1,2,3},{4,5},{6,7,8}},下列哪个式子为真( )
设a={a, æ},则下列哪个结论正确.( ).
若,则有( )
已知a={a,b,c},a上的两个二元关系r={
,,},t={,},则=( ).
给定 a={1,2,3},a上的关系r={<1,2>,<1,3>,<2,1>,<2,3>},则r满足的性质是( ).
设,则( )
设a={a,b,c,d}, 则a的幂集中元素的个数为( ).