3．结合图3-3及图3－4解释临界晶核半径r*和形核功ΔG*的意义，以及为什么形核要有一定过冷度。
答：（1）临界晶核半径r*的意义如下：
r ＜r*时，产生的晶核极不稳定，随即消散；
r =r*时，产生的晶核处于介稳状态，既可消散也可生长；
r ＞r*时，不稳定的晶胚转化为稳定晶核，开始大量形核。
故r*表示原先不稳定的晶胚转变为稳定晶核的临界尺寸。
临界形核功ΔG*的意义如下：
表示形核过程系统需克服的能量障碍，即形核“能垒”。只有当ΔG≥ΔG*时，液相才开始形核。
r
图3-4 液态金属r°、r*与T 的关系及临界过冷度ΔT *
（2）形核必须要有一定过冷度的原因如下：
由形核功的公式：
23316???? ?????=?*T H T V G m m S SL σπ （均质形核） he G *? =4cos cos 3231633θ
θπσ+-???
? ??????m S m LS H T V T （非均质形核） 对某种晶体而言，V S 、
均为定值，ΔG *∝ΔT －2，过冷度ΔT 越小，形核功ΔG *越大，ΔT →0时，ΔG *→∞，这表明
过冷度很小时难以形核，所以物质凝固形核必须要有一定过冷度。
成分过冷与热过冷的区别 :
热过冷是由于液体具有较大的过冷度时，在界面向前推移的情况下，结晶潜热的释放而产生的负温度梯度所形成的。可出现在纯金属或合金的凝固过程中，一般都生成树枝晶。
成分过冷是由溶质富集所产生，只能出现在合金的凝固过程中，其产生的晶体形貌随成分过冷程度的不同而不同，当过冷程度增大时，固溶体生长方式由无成分过冷时的“平面晶”依次发展为：胞状晶→柱状树枝晶→内部等轴晶（自由树枝晶）。
成分过冷与热过冷的联系:
m m SL T H 、、?σ
对于合金凝固，当出现“热过冷”的影响时，必然受“成分过冷”的影响，而且后者往往更为重要。即使液相一侧不出现负的温度梯度，由于溶质再分配引起界面前沿的溶质富集，从而导致平衡结晶温度的变化。在负温梯下，合金的情况与纯金属相似，合金固溶体结晶易于出现树枝晶形貌。
1.铸件典型宏观凝固组织是由哪几部分构成的，它们的形成机理如何?
答：铸件的宏观组织通常由激冷晶区、柱状晶区和内部等轴晶区所组成。
表面激冷区的形成：当液态金属浇入温度较低的铸型中时，型壁附近熔体由于受到强烈的激冷作用，产生很大的过冷度而大量非均质生核。这些晶核在过冷熔体中也以枝晶方式生长，由于其结晶潜热既可从型壁导出，也可向过冷熔体中散失，从而形成了无方向性的表面细等轴晶组织。
柱状晶区的形成：在结晶过程中由于模壁温度的升高，在结晶前沿形成适当的过冷度，使表面细晶粒区继续长大（也可能直接从型壁处长出），又由于固-液界面处单向的散热条件（垂直于界面方向），处在凝固界面前沿的晶粒在垂直于型壁的单向热流的作用下，以表面细等轴晶凝固层某些晶粒为基底，呈枝晶状单向延伸生长，那些主干取向与热流方向相平行的枝晶优先向内伸展并抑制相邻枝晶的生长，在淘汰取向不利的晶体过程中，发展成柱状晶组织。
内部等轴晶的形成：内部等轴晶区的形成是由于熔体内部晶核自由生长的结果。随着柱状晶的发展，熔体温度降到足够低，再加之金属中杂质等因素的作用，满足了形核时的过冷度要求，于是在整个液体中开始形核。同时由于散热失去了方向性，晶体在各个方向上的长大速度是相等的，因此长成了等轴晶。
9、分析缩孔的形成过程，说明缩孔与缩松的形成条件及形成原因的异同点。
答：纯金属、共晶成分合金和结晶温度范围窄的合金，在一般铸造条件下按由表及里逐层凝固的方式凝固。由于金属或合金在冷却过程中发生的液态收缩和凝固收缩大于固态收缩，从而在铸件最后凝固的部位形成尺寸较大的集中缩孔。其形成过程如下图所示。
铸件中缩孔形成过程示意图
从图中可以看出，液态金属充满型腔后，由于铸型的吸热作用，其温度下降，产生液态收缩。此时，液态金属可通过浇注系统得到补充，因而型腔始终保持充满状态（图a）。当铸件外表温度降至凝固温度时，铸件表面就凝固成一层固态外壳，并将内部液体包住（图b）。这时，内浇口已经凝结。当铸件进一步冷却时，壳内的液态金属因温度降低一方面产生液态
收缩，另一方面继续凝固使壳层增厚并产生凝固收缩；与此同时，壳层金属也因温度降低而发生固态收缩。如果液态收缩和凝固收缩造成的体积缩减等于固态收缩引起的体积缩减，则壳层金属和内部液态金属将紧密接触，不会产生缩孔。但是，由于金属的液态收缩和凝固收缩大于壳层的固态收缩，壳内液体与外壳顶面将发生脱离（图c）。随着冷却的进行，固态壳层不断加厚，内部液面不断下降。当金属全部凝固后，在铸件上部就形成了一个倒锥形的缩孔（图d）。
形成缩松和缩孔的基本原因是相同的，即金属的液态收缩和凝固收缩之和大于固态收缩。但形成条件是不同的：产生缩孔的条件是铸件由表及里逐层凝固。形成缩松的条件是金属的结晶温度范围较宽，倾向于体积凝固或同时凝固方式。
新视野英语教程（读写教程第二版）第二册 课后练习参考答案 前言 郑树棠编著的《新视野英语教程》(第二版)是一套专供全国高职高专院校使用的英语教材，根据高职高专英语教学的发展在第一版基础上进行了修订与完善。本套教材贯彻应用为本的设计理念，体现新时期高职英语的教学要求，涵盖基本的实用英语语言知识和交际技能，培养学生应用英语进行日常交流及从事相关职业活动的能力，同时提高他们的自主学习能力与综合文化素养，以适应不同工作岗位的需要。《新视野英语教程》(第二版)包含《读写教程》与《听说教程》两条主线，1-4级由浅入深，满足不同起点学生的需要。除课本外，提供学习光盘、助教课件与试题库等立体化教学资源，全方位支持英语教学。 新视野英语教程（读写教程第二版）图书在淘宝网发售，欢迎购买.
Unit 1 Key to Exercises Section B Reading out 1. peace 2. but 3. Even so 4. by 5. taking 6. in Getting the Message 1. Downey, California; 1953 2. the building was damaged in an earthquake and the restaurant is losing money 3. they have good memories of that old McDonald’s 4. rewrite the history 5. tell the story of the first McDonald’s and show different attitudes of different people towards the restaurant Using the Right Word 1. location b. denied 3. amount 4. damage 5. claim 6. actually 7. inspecting 8. structures Working with Expressions 1. in 2. with 3. of 4. from 5. down 6. away 7. with 8. down Focusing on Sentences Structure A 1. There is no room for four people on the back seat of the car. 2. There is room for 50 people in this restaurant. 3. This is an order: there is no room for argument. B 1. He raised the radio close to his car. Even so, he could not hear anything at all. 2. The team was defeated again yesterday. Even so, there is still hope to win in the final round. 3. The man had not received any formal education, but even so, he became a famous writer. Translating A
新视野大学英语读写教程2 第一单元 1. charge 2. convention 3. efficient 4. obtain 5. competent 6. asessing 7. fulfill 8. conducting 9. consequently 10. significance IV. 1. behind 2. at 3. in 5. to 6. to 10. for V. 1. L 2. C 4. N 5. O 7. E 10. K Word Building VI. 2. attraction 3. appointment 5. civilization 11. acquisition VII. 4. considerable 5. remarkable Sentence Structure VIII. less can he write English articles less can he manage a big company less could he carry it upstairs less have I spoken to him less to read a lot outside of it IX. meals at home can cost as little as two or three dollars, whereas eating out at a restaurant is always more expensive. thought she was rather proud,whereas in fact she was just very shy. have never done anything for them, whereas they have done so much for us. prefers to stay for another week, whereas her husband prefers to leave immediately. praise him highly,whereas others put him down severely. Translation X. wouldn't take a drink, much less could she stay for dinner. thought I was lying to him,whereas I was telling the truth. do you account for the fact that you have been late every day this week increase in their profits is due partly to their new market strategy. measures are likely to result in the improvement of work efficiency. have already poured a lot of time and energy into the project, so we have to carry on. XI. 1.我认为他不会抢劫,更不用说暴力抢劫了. 2.男工平均工资每小时10美元,而女工才每小时7美元. 3.自然界的平衡一旦遭到破坏,就会带来很多不可预知的影响. 4.期终考试迫在眉睫,你最好多花点时间看书. 5.有趣的是,消费者发现越来越难以辨别某些品牌的原产国.其部分原因来自于全球化带来的影响,部分原因是由于产地的变化. 6.最近一次调查表明,妇女占总劳动力的40%.
医学统计学第七版课后答案及解析
医学统计学第七版课后答案 第一章绪论 一、单项选择题 答案 1. D 2. E 3. D 4. B 5. A 6. D 7. A 8. C 9. E 10. D 二、简答题 1答由样本数据获得的结果，需要对其进行统计描述和统计推断，统计描述可以使数据更容易理解，统计推断则可以使用概率的方式给出结论，两者的重要作用在于能够透过偶然现象来探测具有变异性的医学规律，使研究结论具有科学性。 2答医学统计学的基本内容包括统计设计、数据整理、统计描述和统计推断。统计设计能够提高研究效率，并使结果更加准确和可靠，数据整理主要是对数据进行归类，检查数据质量，以及是否符合特定的统计分析方法要求等。统计描述用来描述及总结数据的重要特征，统计推断指由样本数据的特征推断总体特征的方法，包括参数估计和假设检验。 3答统计描述结果的表达方式主要是通过统计指标、统计表和统计图，统计推断主要是计算参数估计的可信区间、假设检验的P 值得出相互比较是否有差别的结论。 4答统计量是描述样本特征的指标，由样本数据计算得到，参数是描述总体分布特征的指标可由“全体”数据算出。 5答系统误差、随机测量误差、抽样误差。系统误差由一些固定因素产生，随机测量误差是生物体的自然变异和各种不可预知因素产生的误差，抽样误差是由于抽样而引起的样本统计量与总体参数间的差异。 6答三个总体一是“心肌梗死患者”所属的总体二是接受尿激酶原治疗患者所属的总体三是接受瑞替普酶治疗患者所在的总体。 第二章定量数据的统计描述 一、单项选择题 答案 1. A 2. B 3. E 4. B 5. A 6. E 7. E 8. D 9. B 10. E 二、计算与分析
define the word resent the treatment frustrate the students declare war evaluate the result perform one’s duty narrow the gap expand business present the facts decorate a room be my haunting memory take a deep breath give a hint stretch one's neck drift on the river let it go at that prick up its ears ripple in the breeze hover over the trees a bond between brothers a carpet for you to walk on snap the door to be serious out of proportion to the occasion go for a picnic put one's arms round her scratch each other’s backs Publish or perish. make RMB convertible seek the truth discard conventions satirize people’s vanity and extravagance The island is uninhabited, and being without drinking water, is also uninhabitable. admire their courage/guts/bravery neglect one’s duty escape/avoid the consequence erase/delete sth from one’s memory take command block the way / stand in the way / be in one’s way ruin one’s reputation/name
新视野大学英语读写教程第二版第二册课后练习答案 新视野大学英语（第二版）第二册Unit 1答案 Unit 1 Section A I Comprehension of The Text 1. The attitude is that if one is not moving ahead heis falling behind. 2. Time is treated as if it were something almostreal. (People budget it, waste it, steal it, kill it, cut it, account for it;they also charge for it.) They do this because time is a precious resource. 3. Everyone is in a rush —often under pressure. City people always appear to be hurrying to get wherethey are going, restlessly seeking attention in a store or elbowing others asthey try to complete their shopping. 4. Don’t take it personally. This isbecause people value time highly and they resent someone else “wasting” it beyond a certain appropriatepoint. 5. New arrivals in America will miss opening exchanges,the ritual interaction that goes with a cup of coffee or tea and leisurelychats. 6. Americans produce a steady flow of labor-savingdevices. They communicate rapidly through faxes, phone calls or emails ratherthan through personal contacts. 7. The impersonality of electronic communication haslittle or no relation to the significance of the matter at hand. 8. It is taken as a sign of skillfulness or beingcompetent to solve a problem or fulfill a job with speed in the U.S. Vocabulary III 1. charge 2. convention 3. efficient 4. obtain 5. competent 6. assessing 7.fulfill 8. conducting consequently 10. significance IV． 1．behind 2. at 3. in 4. out 5. to 6.to 7. in 8. with 9. but 10.for V. 1. L 2. C 3. D 4. N 5. O 6.A 7.E 8.G 9.I 10.K Word Building VI 1. commitment 2. attraction 3. appointment 4.impression 5. civilization 6. composition 7. confusion 8.congratulation 9. consideration 10. explanation 11. acquisition 12.depression VII. desirable favorable considerable acceptable drinkable advisable remarkable preferable 1. advisable 2.desirable 3. favorable 4. considerable 5. remarkable 6. preferable 7. drinkable 8. acceptable Structure VIII 1. much less can he write English articles 2. much less can he manage a big company 3. much less could he carry it upstairs
Unit 1 Language in mission Text A An impressive English lesson Ex.1 Understanding the text 1、Because he is tired of listening to his father and he is not interested in grammar rules. 2、The civilization of Greece and the glory of Roman architecture are so marvelous and remarkable that they should be described at least in a brief account; however, what the student could do was only one single utterance :“whoa!”without any any specific comment. 3、Because the schools fail to set high standards of language proficiency. They only teach a little grammar and less advanced vocabulary. And the younger teachers themselves have little knowledge of the vital structures of language. 4、Because teaching grammar is not an easy job and most of the students will easily get bored if it’s not properly dealt with. 5、He familiarized his son with different parts of speech in a sentence and discussed their specific grammatical functions including how to use adverbs to describe verbs. 6、Because the son had never heard about the various names and functions of words in an English sentence before. 7、The author uses “road map”and “car”to describe grammar and vocabulary. Here,“road map”is considered as grammar and “car”as vocabulary. 8、Since the subjunctive mood his son used is a fairly advanced grammar structure, the interjection“whoa!”reflects the tremendous pride the father had toward his son; it also reflects the author’s humor in using the word because it was once used by his student, though in two different situations and with two different feelings. Ex.3 Words in use 1.condense 2.exceed 3.deficit 4.exposure 5.asset 6.adequate https://www.doczj.com/doc/e73596855.html,petent 8.adjusting 9.precisely 10.beneficial Ex.4 Word building -al/-ial: managerial/editorial/substance/survival/tradition/margin -cy : consistency/accuracy/efficient -y : recovery/ministry/assembly Ex.5 Word building
医学统计学第七版部分课后答案及解析 第二章 1.答：在统计学中用来描述集中趋势的指标体系是平均数，包括算术均数，几何均数，中位数。 均数反映了一组观察值的平均水平，适用于单峰对称或近似单峰对称分布资料的平均水平的描述。 几何均数：有些医学资料，如抗体的滴度，细菌计数等，其频数分布呈明显偏态，各观察值之间呈倍数变化(等比关系)，此时不宜用算术均数描述其集中位置，而应该使用几何均数（geometric mean）。几何均数一般用G表示，适用于各变量值之间成倍数关系，分布呈偏态，但经过对数变换后成单峰对称分布的资料。 中位数和百分位数： 中位数（median）就是将一组观察值按升序或降序排列，位次居中的数，常用M表示。理论上数据集中有一半数比中位数小，另一半比中位数大。中位数既适用于资料呈偏态分布或不规则分布时集中位置的描述，也适用于开口资料的描述。所谓“开口”资料，是指数据的一端或者两端有不确定值。 百分位数（percentile）是一种位置指标，以P X表示，一个百分位数P X将全部观察值分为两个部分，理论上有X％的观察值比P X小，有（100-X）％观察值比P X大。故百分位数是一个界值，也是分布数列的一百等份分割值。显然，中位数即是P50分位数。即中位数是一特定的百分位数。常用于制定偏态分布资料的正常值范围。 2.答：常用来描述数据离散程度的指标有：极差、四分位数间距、标准差、方差、 及变异系数，尤以方差和标准差最为常用。 极差（range，记为R），又称全距，是指一组数据中最大值与最小值之差。极差大，说明资料的离散程度大。用极差反映离散程度的大小，简单明了，故得到广泛采用，如用以说明传染病、食物中毒等的最短、最长潜伏期等。其缺点是：1.不灵敏； 2.不稳定。 四分位数间距（inter-quartile range）就是上四分位数与下四分位数之差，即：Q＝Q U－Q L,其间包含了全部观察值的一半。所以四分位数间距又可看成中间一半观察值的极差。其意义与极差相似，数值大，说明变异度大；反之，说明变异度小。常用于描述偏态分布资料的离散程度。 极差和四分位数间距均没有利用所研究资料的全部信息，因此仍然不足以完整地反映资料的离散程度。 方差（variance）和标准差（standard deviation）由于利用了所有的信息，而得到了广泛应用，常用于描述正态分布资料的离散程度。 变异系数（coefficient of variance，CV）亦称离散系数（coefficient of dispersion），为标准差与均数之比，常用百分数表示。变异系数没有度量衡单位，常用于比较度量单位不同或均数相差悬殊的两组或多组资料的离散程度。 3.答：常用的相对数指标有：比，构成比和率。 比（ratio），又称相对比，是A、B两个有关指标之比，说明A为B的若干倍或百分之几，它是对比的最简单形式。其计算公式为比＝A/B 率(rate)又称频率指标，用以说明某现象发生的频率或强度。常以百分率(％)、千
新视野大学英语（第三版）第二册读写教程课后答案Unit 1 Language in mission Text A An impressive English lesson Ex.1 Understanding the text 1、Because he is tired of listening to his father and he is not interested in grammar rules. 2、The civilization of Greece and the glory of Roman architecture are so marvelous and remarkable that they should be described at least in a brief account; however, what the student could do was only one single utterance :“whoa!” without any any specific com ment. 3、Because the schools fail to set high standards of language proficiency. They only teach a little grammar and less advanced vocabulary. And the younger teachers themselves have little knowledge of the vital structures of language. 4、Because teaching grammar is not an easy job and most of the students will easily get bored if it’s not properly dealt with. 5、He familiarized his son with different parts of speech in a sentence and discussed their specific grammatical functions including how to use adverbs to describe verbs. 6、Because the son had never heard about the various names and functions of words in an English sentence before. 7、The author uses “road map”and “car”to describe grammar and vocabulary. Here,“road map”is considered as grammar and “car”as vocabulary. 8、Since the subjunctive mood his son used is a fairly advanced grammar structure, the interjection“whoa!”reflects the tremendous pride the father had toward his son; it also reflects the author’s humor in using the word because it was once used by his student, though in two different situations and with two different feelings. Ex.3 Words in use 1.condense 2.exceed 3.deficit 4.exposure 5.asset 6.adequate https://www.doczj.com/doc/e73596855.html,petent 8.adjusting 9.precisely 10.beneficial Ex.4 Word building -al/-ial: managerial/editorial/substance/survival/tradition/margin -cy : consistency/accuracy/efficient -y : recovery/ministry/assembly Ex.5 Word building 1.editorial 2.recovery 3.accuracy 4.substance 5.managerial 6.margin 7.assembly 8.Ministry 9.survival 10.tradition 11.consistency 12.efficient
Unit 1 III 1 beneath 2 disguised 3 whistles 4 restrain 5 grasp 6 longing 7 praying 8 faithful 9 pledge 10 drain IV 1 tell … on you 2 track down 3 work it out 4 picking on me 5 reckoned with 6 call on 7 on his own 8 get through 9 in disguise 10 revolves around V.. G O D I K L B F A N VI 1 advise 2 level 3 problems 4 necessity 5 skills 6 experience 7 solution 8 value 9 tool 10 manner VII 1 air-conditioned( 装空调的；有冷气的) 2 handmade （手工制作的） 3 thunderstruck （非 常吃惊的） 4 heartfelt （衷心的；诚挚的） 5 data-based （基于数据的） 6 self-employe d
（自主经营的）7 custom-built （定制的；定做的）8 weather-beaten （饱经风霜的） VIII 1. well-informed （对…… 非常熟悉的）2 new-found （新获得的）3 hard-earned （辛苦挣得 的） 4 soft-spoken （说话温柔的） 5 newly-married （新婚的） 6 widely-held （普遍认为的） 7 well-meant （出于好意的）8 well-educated （受过良好教育的）IX 1 no matter how different it may seem form any other substance 2 no matter what a woman tries to do to improve her situation 3 no matter what excuse he gives 4 no matter what anyone else may think 5 no matter how they rewrite history X 1 just as we gained fame in victory, we lost nothing in defeat 2 just as the head teacher plays a significant role in the school, Jane plays a significant role f leader in the classroom.
练习题答案 第一章医学统计中的基本概念 练习题 一、单向选择题 1. 医学统计学研究的对象是 A. 医学中的小概率事件 B. 各种类型的数据 C. 动物和人的本质 D. 疾病的预防与治疗 E．有变异的医学事件 2. 用样本推论总体，具有代表性的样本指的是 A．总体中最容易获得的部分个体 B．在总体中随意抽取任意个体 C．挑选总体中的有代表性的部分个体 D．用配对方法抽取的部分个体 E．依照随机原则抽取总体中的部分个体 3. 下列观测结果属于等级资料的是 A．收缩压测量值 B．脉搏数 C．住院天数 D．病情程度 E．四种血型 4. 随机误差指的是 A. 测量不准引起的误差 B. 由操作失误引起的误差 C. 选择样本不当引起的误差 D. 选择总体不当引起的误差 E. 由偶然因素引起的误差 5. 收集资料不可避免的误差是 A. 随机误差 B. 系统误差 C. 过失误差 D. 记录误差 E．仪器故障误差 答案: E E D E A 二、简答题 1.常见的三类误差是什么？应采取什么措施和方法加以控制？ [参考答案] 常见的三类误差是：
（1）系统误差：在收集资料过程中，由于仪器初始状态未调整到零、标准试剂未经校 正、医生掌握疗效标准偏高或偏低等原因，可造成观察结果倾向性的偏大或偏小，这叫系统误差。要尽量查明其原因，必须克服。 （2）随机测量误差：在收集原始资料过程中，即使仪器初始状态及标准试剂已经校正， 但是，由于各种偶然因素的影响也会造成同一对象多次测定的结果不完全一致。譬如，实验操作员操作技术不稳定，不同实验操作员之间的操作差异，电压不稳及环境温度差异等因素 造成测量结果的误差。对于这种误差应采取相应的措施加以控制，至少应控制在一定的允许范围内。一般可以用技术培训、指定固定实验操作员、加强责任感教育及购置一定精度的稳 压器、恒温装置等措施，从而达到控制的目的。 （3）抽样误差：即使在消除了系统误差，并把随机测量误差控制在允许范围内，样本 均数（或其它统计量）与总体均数（或其它参数）之间仍可能有差异。这种差异是由抽样引 起的，故这种误差叫做抽样误差，要用统计方法进行正确分析。 2.抽样中要求每一个样本应该具有哪三性？ [参考答案] 从总体中抽取样本，其样本应具有“代表性”、“随机性”和“可靠性”。 （1）代表性: 就是要求样本中的每一个个体必须符合总体的规定。 （2）随机性: 就是要保证总体中的每个个体均有相同的几率被抽作样本。 （3）可靠性: 即实验的结果要具有可重复性，即由科研课题的样本得出的结果所推测 总体的结论有较大的可信度。由于个体之间存在差异, 只有观察一定数量的个体方能体现出 其客观规律性。每个样本的含量越多，可靠性会越大，但是例数增加，人力、物力都会发生 困难，所以应以“足够”为准。需要作“样本例数估计”。 3.什么是两个样本之间的可比性？ [参考答案] 可比性是指处理组（临床设计中称为治疗组）与对照组之间，除处理因素不同外，其他可能影响实验结果的因素要求基本齐同，也称为齐同对比原则。 (马斌荣) 第二章集中趋势的统计描述 练习题 一、单项选择题 1. 某医学资料数据大的一端没有确定数值，描述其集中趋势适用的统计指标是
U n i t1L a n g u a g e i n m i s s i o n Text A An impressive English lesson Ex.1 Understanding the text 1、Because he is tired of listening to his father and he is not interested in grammar rules. 2、The civilization of Greece and the glory of Roman architecture are so marvelous and remarkable that they should be described at least in a brief account; however, what the student could do was only one single utterance :“whoa!” without any any specific comment. 3、Because the schools fail to set high standards of language proficiency. They only teach a little grammar and less advanced vocabulary. And the younger teachers themselves have little knowledge of the vital structures of language. 4、Because teaching grammar is not an easy job and most of the students will easily get bored if it’s not properly dealt with. 5、He familiarized his son with different parts of speech in a sentence and discussed their specific grammatical functions including how to use adverbs to describe verbs. 6、Because the son had never heard about the various names and functions of words in an English sentence before. 7、The author uses “road map”and “car”to describe grammar and vocabulary. Here,“road map”is considered as grammar and “car”as vocabulary. 8、Since the subjunctive mood his son used is a fairly advanced grammar structure, the interjection“whoa!”reflects the tremendous pride the father had toward his son; it also reflects the author’s humor in using the word because it was once used by his student, though in two different situations and with two different feelings. Ex.3 Words in use
) 统计学原理第七版李洁明-课后选择判断题习题及答案 一、单项选择题 1.统计有三种含义，其基础是（）。 （1）统计学（2）统计活动（3）统计方法（4）统计资料 2.一个统计总体（）。 （1）只能有一个标志（2）只能有一个指标（3）可以有多个标志（4）可以有多个指标3.下列变量中，（）属于离散变量。 （1）一包谷物的重量（2）一个轴承的直径（3）在过去一个月中平均每个销售代表接触的期望客户数（4）一个地区接受失业补助的人数 < 4.某班学生数学考试成绩分别为65分、71分、80分和87分，这四个数字是（）。（1）指标（2）标志（3）变量（4）标志值 5.下列属于品质标志的是（）。 （1）员工年龄（2）员工性别（3）员工体重（4）员工工资 6.现要了解某机床企业的生产经营情况，该企业的产量和利润是（） （1）连续变量（2）离散变量（3）前者是连续变量，后者是离散变量 （4）前者是离散变量，后者是连续变量
7.劳动生产率是（） | （1）动态指标（2）质量指标（3）流量指标（4）强度指标 8.统计规律性主要是通过运用（）方法经整理、分析后得出的结论（1）统计分组法（2）大量观察法（3）综合指标法（4）统计推断法 9.（）是统计的基础功能。 （1）管理功能（2）咨询功能（3）信息功能（4）监督功能 10.（）是统计的根本准则，是统计的生命线。 （1）真实性（2）及时性（3）总体性（4）连续性 11.构成统计总体的必要条件是（） 《 （1）差异性（2）综合性（3）社会性（4）同质性 12.数理统计学的奠基人是（）。 （1）威廉·配第（2）阿亨瓦尔（3）凯特勒（4）恩格尔 13.统计研究的数量必须是（）。 （1）抽象的量（2）具体的量（3）连续不断的量（4）可直接相加的量14.最早使用统计学这一学术用语的是（） （1）政治算术学派（2）社会统计学派（3）国势学派（4）数理统计学派
Lesson Two How Reading Changed My Life V ocabulary 1 Translate Into Chinese 1). a work of art 一件艺术品 2). bargain basement 便宜货；廉价商品区 3)printing press 印刷（机） 4)the source of quotation 引文出处 5)literary criticism 文学批评 6)in the latter half of the century 该世纪后半叶 7) a liberal arts college 文理学院 8) a man of action 实干家，说干就干的人 9）intellectual pursuits 对知识的追求；学习与研究 10）national character 民族性格 11）domino effect 多米诺骨牌效应 12）a tool for advancement 一种提升的工具，提高（自己）的方法 13）hale and hearty (美)健壮的，矍铄的 14）the virtues of reading 阅读的益处（好处） 15）a sense of superiority 一种优越感 Into English 1) 免予恐惧be free from fear (panic) 2) 从他父亲那里继承财产to inherit property from his father 3) 和学生互动to interact with students 4) 给年轻人作榜样to set an example for the youths (to act as a model for young people) 5）对挑战作出反应to react/respond to challenges 6) 反抗压迫to rebel against oppression 7) 渴望成功to aspire to success 8) 怀疑他们的动机be suspicious of their motives 9) 认真记住历史教训commit the lessons of history to memory 10) 向这些人让步give way to these people 11）将这地区一分为二to divide this region into two parts 12) 干涉我们的内部事务to interfere with our internal affairs 13) 主修土木工程to major in civil engineering 14) 把他们从绝望中救出来to save them from despair 15) 导致经济萧条to result in economic recession/slump/depression 3.Fill in the blanks with appropriate words. 1)into, in, with, for 2)to, to, 3)of, at, up, in, against