课后练习答案Unit_7_The_chaser
Unit 7 The chaser.
Vocabulary
1. Explain the underlined part in each sentence in your own words
(1) feeling very much worried and afraid;
(2) everything I sell could be well deemed as extraordinary;
(3) difficult to notice; which is more than enough;
(4) have much more everlasting effects than only the momentary impulse; (5) with extreme happiness and enthusiasm 2. Fill in the blank in each sentence with a word taken from the box in the proper form.
(1)creaky; (2)peered; (3)acquaintance; (4)detachment;
(5)raptures; (6)giddy; (7)overwhelmed; (8)obliged
3. Fill in the blanks with the appropriate forms of the given words.
(1)obscurity; (2)acquainted; (3)perceptible; (4)apprehension;
(5)indifferent; (6)rapt; (7)overwhelmingly; (8) disobliging
4.Fill in the blank in each sentence with an appropriate phrasal verb or collocation taken from the text.
(1)save up; (2)care about; (3)indulges in; (4)reached for;
(5)peered about; (6)deals in; (7)was substituted; (8)better off.
5. Give a synonym or an antonym of the word underlined in each sentence in the sense it is used.
(1) perceptible (perceivable, noticeable); (2) postmortem;
(3)anxiously (fearfully); (4)temporary (transient);
(5) grave(cheerless); (6) profoundly(rigorously, strongly);
(7) apathetically(indifferently); (8) reason;
6. Explain the underlined phrasal verbs in your own words.
(1)expect; (2)have; (3)accept; (4)imagine;
(5)was; (6)work out;(7)became popular;(8)demanded
Grammar.
https://www.wendangku.net/doc/1a2485599.html,plete each sentence with what you think the most appropriate of the four choices given.
1~4 CDAB 5~8 BCDC
Translation.
1. To me, you are definitely more than an acquaintance.
2. Many artisans deal in a variety of handicrafts in the region.
3. They went into raptures over the unexpected success.
4. Much to my surprise, he analyzed with detachment the dangerous situation that threatened all of them.
5. She peered at the strange from behind the curtain.
6. During the holidays, he indulged in the luxury of a bath of sunshine on the beach.
7. When she learnt the news of his death, she was overwhelmed with grief.
8. I’m not in favor of buying a house on the installment plan; instead, I maintain that everyone of us should save up for a rainy day.
Exercises for integrated skills.
2. Fill in each blank in the passage below with ONE word you think appropriate.
(1)if (2) no (3)through (4)with (5)does (6)that (7)want (8)Here (9)sung (10)and (11)but (12)upon (13)precious (14)nor
外贸函电课后练习答案
Unit 2 Establishing Business Relations & Inquiring Credit Reference I. Translate the following sentences into English. 1. We are one of the leading importers dealing in electronic products in the area, and take this opportunity to approach you, in the hoping of establishing business relations. 2. We have been engaged in handling importing and exporting of machinery and equipment for many years, and our products have enjoyed great popularity in many countries. 3. We owe your name and address to the Commercial Counselor’s office of our Embassy in Beijing. 4. We are given to understand that you are a manufacturer of daily chemicals. One of our clients intends to buy cosmetics from your country. We will appreciate it highly if you airmail the catalogue and price list of the goods available at present. 5. For our credit standing, please refer to the Bank of China, Shanghai Branch. II. Write a letter Dear Sirs, We have obtained your name and address from the Commercial Counsel of your Embassy in Beijing and are pleased to write to establish business relations with you. We are informed that you are in the market for Chinese Cotton Piece Goods, and this item falls with the scope of our business activities. To acquaint you with our goods available for export, we are enclosing a catalogue and price list. We are looking forward to your early reply. Faithfully yours, Unit 3 Enquiries and Replies II. Translate the following sentences into English. 1. Please quote us your best price CIF Shanghai, including our 3% commission. 2. Should your price be found competitive, we intend to place an order with you for 300,000 yards of Cotton Cloth. 3. One of our customers is now interested in the Qingdao Haier Refrigerator made in your country. Please offer CIF London for 400 sets to be delivered in April.
《最新英美概况》练习参考答案(美国部分)
《最新英美概况》 练习参考答案 （本答案不包括练习中的开放性习题、思考题和讨论题） ==================================================== PART TWO The United States Chapter Eight The Land P. 209—210 I Fill in the blanks with proper words or expressions. 1. the Star-Spangled Banner, Defense of Fort McHenry, 181 2. 2. the Stars and the Stripes, Old Glory, the Star-Spangled Banner. 3. The White House, The Capitol, The Pentagon. 4. June, 14th, June 14th. 5. the Potomac, no state, the Federal government. 6. 36, 36 states. 7. Amerigo Vespucci, American War of Independence. 8. Pierre L’Enfant, light, service. II Choose the answer that best completes the sentence. 1. C 2. D 3. C 4. A B C D 5. C D III Decide which of the following statements is TRUE: 1. F 2. F 3. T 4. F 5. T IV Answer the following questions. 1. (1) At first the Continent was named as “America” after explorer Amerigo Vespucci. (2) During the American War of Independence, the former British colonies first used “the thirteen united States of America” in the Declaration of Independence. (3) The official name of America was adopted on November 15, 1777, when the Second Continental Congress passed the Articles of Confederation. 2. The 50 stars represent the 50 States, while the 13 stripes represent the original thirteen colonies. White indicates purity and innocence; red indicates valour and bravery, and blue symbolizes vigilance, perseverance and justice; it is also a symbol of respect to God. 3. The stars and strips have different meanings. Each star represents each state in America, while strips represent the original thirteen colonies before the independence of America.
第三章 练习题答案
第三章练习题 一、判断正误并解释 1.所谓商品的效用，就是指商品的功能。 分析：这种说法是错误的。商品的效用指商品满足人的欲望的能力，指消费者在消费商品时所感受到的满足程度 2.不同的消费者对同一件商品的效用的大小可以进行比较。 分析：这种说法是错误的。同一个消费者对不同商品的效用大小可以比较。但由于效用是主观价值判断，所以同一商品对不同的消费者来说，其效用的大小是不可比的。 3.效用的大小，即使是对同一件商品来说，也会因人、因时、因地而异。分析：这种说法是正确的。同一商品给消费者的主观心理感受会随环境的改变而改变。 4.边际效用递减规律是指消费者消费某种消费品时，随着消费量的增加，其最后一单位消费品的效用递减。 分析：这种说法是错误的。必须在某一特定的时间里，连续性增加。5.预算线的移动表示消费者的货币收入发生变化。 分析：这种说法是错误的。只有在收入变动，商品价格不变，预算线发生平移时，预算线的移动才表
示消费者的收入发生了变化。 6.效应可以分解为替代效应和收入效应，并且替代效应与收入效应总是反向变化。 分析：这种说法是错误的。正常物品的替代效应和收入效应是同向变化的。 二、选择 1.当总效用增加时，边际效用应该：（A ） A.为正值，但不断减少； B.为正值，且不断增加； C.为负值，且不断减少； D.以上都不对 ２.当某消费者对商品Ｘ的消费达到饱合点时，则边际效用ＭＵχ为：（C ） Ａ.正值Ｂ.负值Ｃ.零Ｄ.不确定 ３.正常物品价格上升导致需求量减少的原因在于：（C ） Ａ.替代效应使需求量增加，收入效应使需求量减少； Ｂ.替代效应使需求量增加，收入效应使需求量增加；
国际结算第三章 课后练习和答案(中文)
第三章课后练习和答案（一） 一、选择题（包括单选和多选） 1、我们说票据的无因性是指（）。 A、出票人出票没有原因 B、票据成立与否取决于出票的原因 C、票据的付款是无条件的 分析：正确答案应为C。我们所指的票据的无因性是指汇票、支票的付款是无条件命令，本票的付款是无条件承诺。 2、本票分为一般本票和银行本票两种，一般本票指的是出票人为企业或个人，付期期限为（）的本票 A.即期 B.远期 C.既可以是即期也可以是远期 D.远期180天以内。 分析：正确答案应为C。本票实际上就是付款人为出票人自身的特殊汇票，大多数国家没有专门的本票法，本票视同为汇票，因此本票的期限和汇票是一致的，本票可以是即期的，也可以是远期的。（注意：由于不同国家的法律环境不同，因而不同的国家对票据的期限会有不同的规定）。 3、银行承兑汇票的出票人应为（）。 A、银行 B、商业企业 C、银行或商业企业 分析：正确答案应为B。银行承兑汇票就出票人而言属于商业汇票，为补充商业汇票流通性不足的缺陷，银行应出票人或其他人的请求对汇票予以承竞。 4、拒绝证书是持票人在提示票据遭到拒付或拒绝承兑后向公证机构申请办理的一种证明文件。制作拒绝证书的主要目的是（）。 A.持票人可以合法地要求付款退货 B.持票人可以合法地向前手行使追索权 C.证明托收单据由持票人合法持有 D.证明付款人的行为严重违背《合同法》中的有关规定 分析：正确答案应为B。票据持有人向付款人提示票据，遭到拒付或拒绝承兑时，必须作拒绝证书，其主要目的是合法地向前手行使追索权。 5、票据的善意持票人是指（），取得了一张表面完整、合格的、有效的持票人。 A、虽未付对价，但由别人无偿赠予 B、善意地付了票据的全部对价 C、无意中拾到，但找不到失主 D、从他人手上低价购得 分析：正确答案应为B。票据的善意持票人就是指支付了票据的全部金额的持票人。 6、.以下何种背书属于空白背书（）。 A、Pay to the order of Henry Brown B、Pay to Henry Brown only C、William White William White William White 分析：正确答案应为C。所谓空白背书是指仅转让人签署了自身的姓名，而没有被转让人的姓名。 7、.在承兑交单方式下，如果托收单据中附有汇票，则应要求付款人在汇票上进行承兑。承兑的内容一般应包括（）。 A.“承兑”字样 B.承兑日期或到期日 C.承兑人签字 D.承兑人地址 分析：正确答案应为ABC。承兑地址是多余的，是没有必要的。 8、.关于汇票的付款时间，如果提示日为4月20日，票面上写明“At 90 days from sight”，则到期日付
英美概况课后习题答案
1. What is the full name of the U.K.? ----United Kingdom of Great Britain and Northern Ireland 2. Why do tourists from all over the world like to go to Scotland? ----They like to enjoy the beautiful Scottish scenery, to drink Scotch whisky and to see Scotsmen wearing kilts and playing bagpipes. 3. How many periods can the development of the English language be divided into and what are they? ----The development of the English language can be divided into three periods: Old English, Middle English and Modern English. 4. Why did English become more important after Black Death? ----The laboring and merchant classes grew in economic and social importance after the Black Death, so English also grew in importance compared to French. 1. Who are the British People? ----The first known inhabitants in Britain were Celts who are the ancestors of the Welsh, Scottish and Irish people. Then came the Anglos, the Saxons and the Jutes who brought with them the English language. Many people from other European countries came later, and in modern times there are a lot of immigrants from many former Commonwealth countries from every part of the world. Britain is a country of mixed cultures, and the Britain people are also composed of people from different ethic and culture backgrounds. 2. What is Standard English? ----Standard English is based on the speech of the upper class of southeastern England. It is widely used in media and taught at schools. It is preferred by the educated, middle-class people. It has developed and has been promoted as a model for correct Britain English. It is also the norm carried overseas. Today, Standard English is codified to the extent that the grammar and vocabulary are much the same everywhere in the world where English is taught and used. 1. What are the two components of the British Parliament? ----the House of Commons and the House of Lords. 2. What were some of Queen Victoria's major achievement? ---- Queen Victoria made tremendous achievements in almost every aspect.
第三章作业及答案
第三章练习题及参考答案 一、材料分析题 1.分析下列关于人民群众在历史上的作用问题的不同观点： 【材料1】 孟轲说：“民为贵，社稷次之，君为轻。”荀子认为：“君者，舟也；庶人者，水也。水则载舟，水则覆舟。” 【材料2】 梁启超说：“大人物心理之动进稍易其轨而全部历史可以改观”,“舍英雄几无历史”。胡适说：英雄人物“一言可以兴邦，一言可以丧邦”。 【材料3】 黑格尔认为，历史不是个人随意创造的，而是决定于某种“客观精神”。伟大人物是“世界精神的代理人”，拿破仑代表了“世界精神”，他“骑着马，驰骋全世界，主宰全世界”。世界历史是伟大人物和王朝的历史，“而不是一般人民的历史”。 【材料4】 AHA12GAGGAGAGGAFFFFAFAF
毛泽东说：“人民，只有人民，才是创造世界历史的动力。”马克思说：“人们自己创造自己的历史，但是他们并不是随心所欲地创造，并不是在他们自己选定的条件下创造，而是在直接碰到的，既定的，从过去承继下来的条件下创造。” 【材料5】 马克思指出：“如爱尔维修所说的，每一个社会时代都需要有自己的伟大人物，如果没有这样的人物，它就要创造出这样的人物来。”恩格斯也说：“恰巧某个伟大人物在一定时间出现于某一国家，这当然纯粹是一种偶然现象。但是，如果我们把这个人除掉，那时就会需要有另外一个人来代替它，并且这个代替者是会出现的。 AHA12GAGGAGAGGAFFFFAFAF
” 请回答： ⑴材料1思想的合理性和局限性。 ⑵分别指出材料2和材料3的思想倾向，说明材料2和材料3的共同点。 ⑶材料4是什么观点? 材料5体现了什么思想？ 2．用有关历史发展规律性的原理分析下列材料： 【材料1】 人们必须认识到，人类进步能够改变的只有其速度，而不会出现任何发展顺序的颠倒或跃过任何重要的阶段。（摘自孔德：《实证哲学》） 【材料2】 一个国家应该而且可以向其他国家学习。一个社会即使探索到了本身运动的自然规律，……它还是既不能跳过也不能用法令取消自然的发展阶段。但是它能缩短和减轻分娩的痛苦。（摘自马克思：《资本论》） 【材料3】 AHA12GAGGAGAGGAFFFFAFAF
外贸函电课后练习答案大全
选择题 第二单元：询价与回复 一：1.You name D. has been recommended to us by the Chamber of Commerce in New York.. 2. Our market survey informs us that you are A. in the market for Audio and Electronic Equipment. 3. We should be pleased to receive you’re A. illustrated catalogue and price list. 4. We are B. well-established exporters of all kinds of Chinese good. 5. If your price are competitive, we are confident D. in selling the goods in great quantities in this market. 6. We shall appreciate B. your quoting us FOB Sydney. 7. As we are one of the leading importers in this line, we are B. in a position to handle large quantities. 第三单元：资信调查 一：1.For information D. concerning our credit standing we refer you to Bank of China, Shanghai Branch. 2. We should be grateful if you would say C. whether they are likely to be reliable for a credit up to USS20.000. 3. Any information you kindly give us will be treated in strict confidence and A. without any responsibility on your part. 4. Will you please inform us, B. in confidence, of the extent of their resources and also as to their reputation? 5. D. While appreciating your decision to place regular orders with us, we respectfully request that you furnish us two references for the initial purchase. 第四单元：促销 1.（C、Having made）a special purchase of toys on very favorable terms, we are able to offer to you at the following attractive prices 2 we can only（A、hold open）this very advantageous offer for a few weeks.. 3 the recent advance in the cost of raw materials （B、has compelled）us to make a slight increase in the Prices 4 although costs have been （C、rising）steadily since last October , we have not yet （raised）our prices 5 （B、with a view to ）supporting your sales, we are sending some samples of our new makes. 第五单元：报盘与还盘 1A comparison of your offer （A、with that of ）our regular suppliers shows that their figures are more favorable. 2 If your prices are competitive, we are confident（D、in selling）the goods in great quantities in this market. 3 we confirm our fax just sent （A、offering you firm）these goods. 4 we offer you the following items（D、subject to）your reply reaching here by 4p.m today our time. 5 although we appreciate good quality of your goods, we are sorry to say that your prices appears to be（C、on the high side）. 6 we trust that we may be （C、favored）with a continuance of your valued orders. 7 we hope that you will see your way to （B、grant）us your order, and assure you in advance of its most careful execution 8 not having heard from you since, we should be glad to know whether there is any disadvantage in our terms which we could （B、remove）. 9 you are （C、assured）that we will quote our best prices as soon as we are told what products of ours you need. 10 in all probability this offer will not be （A、repeated）for some time, and we according look forward to receiving an early reply from you. 第六单元: 订单 一、Fill in the blanks with your choices 1.This order the sample you sent us on March 24.（A、is placed on） 2.We hope you will give your usual best attention this order.（B、to the execution of） 3.We have decided to place a trial order for the following stated in your letter.（B、on the terms） 4.we would like to supply you with the product, we are unable to fill your order owing to the heavy backlog of commitments. (B、Much as) 5.We must apologize you being unable to fill your present order.（D、To… for ） 6.We have accepted your Order No.234. Please open the relevant L/C,here two weeks prior to the date of shipment.（A、which must reach） 7.We are enclosing our latest catalogue some of the items may be of interest to you.（C、in the hope that） 8.The order is given strictly on the condition that shipment must be made not later than the first day of May.（B、enclosed） 第七单元：支付 一、单选 1.As requested, we have immediately arranged (A、with) our bankers to extend the expiry date of our L/C for two weeks (up to) 10th March. 2.As arranged, we would ask you to open an irrevocable credit in (C、our) favor and shall hand over shipping documents (against) acceptance of our draft. 3.We inform you that we have opened an irrevocable credit (D、with) the London Bank in your favor. 4.We advised the bank to amend the clause (D、to read)“partial shipment are permitted”. 5.We enclose our cheque for US$ 200 (A、in payment of) your invoice No.D-124. 第九单元：保险 一：选择题 1: please insure the goods (A、against) F.P.A. for US 100,000. 注：against加险别for加保额 2: please effect insurance (D、on) the cargo for US50,000 by S.S.Bright from Tianjin to seattle. 3: we have opened insurance you ordered for US9,000 (D、on) the shipment by S.S.East sun. 4: we wish to renew the above policy (C、for) the same amount and (on)the same terms as before to cover our consignment to be shipped b s.s.bright next month. 5: as requester, we have covered insurance (on) 20,000 DVD players (at) 10% above the invoice value (against) all risks. 6: unless we hear from you (A、to) the contrary before the end of this month, we shall arrange to cover the goods against t p a for the value of the goods plus freight. 7: any additional coverage（险别）other (B、than) ISS shall be for the account of the buyer. 8: we confirm that we hold the consignment covered as (from) today. 9: we have arranged (A、for) surveyor to investigate the extent of the damage and shall forward his report together with our claim. 10: we understand that these terms will apply (C、to)all our shipments of bottled sherry by regular liners to west European ports. 完形填空 第二单元：Fill in each blank in the letter below with a word that fits naturally.
第三章部分习题答案
第三章部分习题答案 1、高级调度与低级调度的主要任务是什么？为什么要引入中级调度？ 答：高级调度主要任务是根据某种算法，把外存上处于后备队列中的那些作业调入内存，也就是说高级调度的调度对象是作业。 低级调度主要任务是：决定就绪队列中的哪个进程应获得处理机，然后再由分派程序执行把处理机分配给该进程的具体操作。 中级调度的任务：使那些暂时不能运行的进程不再占用宝贵的内存资源，而将它们调至外存上去等待，把此时的进程状态称为就绪驻外存状态或挂起状态。当这些进程重又具备运行条件且内存又稍有空闲时，由中级调度来决定把外存上的那些又具备运行条件的就绪进程重新调入内存，并修改其状态为就绪状态，挂在就绪队列上等待进程调度。引入中级调度的主要目的是为了提高内存利用率和系统吞吐量。 2、何谓作业、作业步和作业流？ 答：作业（Job）：作业是一个比程序更为广泛的概念，它不仅包含了通常的程序和数据，而且还应配有一份作业说明书，系统根据该说明书来对程序的运行进行控制。 作业步(Job Step)。通常，在作业运行期间，每个作业都必须经过若干个相对独立，又相互关联的顺序加工步骤才能得到结果，我们把其
中的每一个加工步骤称为一个作业步，各作业步之间存在着相互联系，往往是把上一个作业步的输出作为下一个作业步的输入。 作业流：若干个作业进入系统后，被依次存放在外存上，这便形成了输入的作业流；在操作系统的控制下，逐个作业进行处理，于是便形成了处理作业流。 5、试说明低级调度的主要功能。 答：(1) 保存处理机的现场信息。 (2) 按某种算法选取进程。 (3) 把处理器分配给进程。 6、在抢占调度方式中，抢占的原则是什么？ 答：(1) 优先权原则。 (2) 短作业(进程)优先原则。 (3) 时间片原则。 7、在选择调度方式和调度算法时，应遵循的准则是什么？ 答：面向用户应遵循的准则是：(1) 周转时间短。(2) 响应时间快。 (3) 截止时间的保证。(4) 优先权准则。 面向系统应遵循的准则是：(1) 系统吞吐量高。(2) 处理机利用率好。(3) 各类资源的平衡利用。
第三章习题与参考答案
第三章习题与参考答案 3-1 输水管路的直径为150㎜输水量为981kN/hr 求断面平均流 速。 （答：1.57m/s ） 3-2 矩形风道的断面为300×400㎜2，风量为2700m 3/hr ，求断面 平均流速，若出风口断面缩小为150×700㎜2，该处的平均流速多大？ （答：6.25m/s,25.0m/s ） 3-3 一圆形风道，风量为10000 m 3/hr ，最大允许流速为20 m/s ， 试设计其直径（应为50㎜的整倍数）并核算其流速. (答：450㎜，17.5 m/s) ， 各为多大才能保证两支管的质量流量相等？ （答：s m v s m v /2.22,/1832==） 3-6 在4×4㎝2的空气压缩机进口管路中，空气的密度委1.2kg/m 3, 平均流速为4m/s ，经过压缩后，在直径为2.5cm 的圆管中，以 3m/s 的平均流速排出，求出口的空气密度和质量流量。 （答：5.22kg/m 3,7.68×10-3kg/s ）
3-7 试比较1和3点流速的大小：1）在等直径立管中，2）在渐 () () () 10107 1 0203; 2; 11? ?? ?????=????????=???? ?????????????=r y u u r y u u r y u u m m m 3-9 已知圆管中的流速分布曲线为7 1 0????????=r y u u m ，求流速等于平均 流速的点离壁面的距离。 c y （答：0242） 0r 3-10 求题（3-8）中各种情况的动能修正系数α值 （答：2，1.057，1.03） 3-11 圆喷嘴在圆管中喷射流体，流速分布如图，已知， mm d 501=
第三章作业答案
{ 思考题 2.下列烯类单体适于何种机理聚合自由基聚合、阳离子聚合还是阴离子聚合并说明原因。 CH 2=CHCl CH 2 =CCl 2 CH 2 =CHCN CH 2 =C(CN) 2 CH 2 =CHCH 3 CH 2 =C(CH 3 ) 2 CH 2=CHC 6 H 5 CF 2 =CF 2 CH 2 =C(CN)COOR CH 2 =C(CH 3 )-CH=CH 2 答：CH 2 =CHCl：适合自由基聚合，Cl原子是吸电子基团，也有共轭效应，但均较弱。 CH 2=CCl 2 ：自由基及阴离子聚合，两个吸电子基团。 CH 2 =CHCN：自由基及阴离子聚合，CN为吸电子基团。 CH 2=C(CN) 2 ：阴离子聚合，两个吸电子基团（CN）。 CH 2=CHCH 3 ：配位聚合，甲基（CH 3 ）供电性弱。 / CH 2=CHC 6 H 5 ：三种机理均可，共轭体系。 CF 2=CF 2 ：自由基聚合，对称结构，但氟原子半径小。 CH 2 =C(CN)COOR：阴离子聚合，取代基为两个吸电子基（CN及COOR） CH 2=C(CH 3 )-CH=CH 2 ：三种机理均可，共轭体系。 3. 下列单体能否进行自由基聚合，并说明原因。 CH 2=C(C 6 H 5 ) 2 ClCH=CHCl CH 2 =C(CH 3 )C 2 H 5 CH 3 CH=CHCH 3 CH 2=CHOCOCH 3 CH 2 =C(CH 3 )COOCH 3 CH 3 CH=CHCOOCH 3 CF 2 =CFCl ： 答：CH 2=C(C 6 H 5 ) 2 ：不能，两个苯基取代基位阻大小。 ClCH=CHCl：不能，对称结构。 CH 2=C(CH 3 )C 2 H 5 ：不能，二个推电子基，只能进行阳离子聚合。 CH 3CH=CHCH 3 ：不能，结构对称。 CH 2=CHOCOCH 3 ：醋酸乙烯酯，能，吸电子基团。 CH 2=C(CH 3 )COOCH 3 ：甲基丙烯酸甲酯，能。 CH 3CH=CHCOOCH 3 ：不能，1，2双取代，位阻效应。 CF 2 =CFCl：能，结构不对称，F原子小。 ; 7.为什么说传统自由基聚合的激励特征是慢引发，快增长，速终止在聚合过程中， 聚合物的聚合度，转化率变化趋势如何 链引发反应是形成单体自由基活性种的反应。此反应为吸热反应，活化能高E = 105～150 kJ/mol，故反应速度慢。链增长反应为放热反应，聚合热约55～
第三章课后习题解答
3.4.1 质量为2kg 的质点的运动学方程为 j t t i t r ?)133(?)16(2 2+++-= （单位：米，秒）， 求证质点受恒力而运动，并求力的方向 大小。 解：∵j i dt r d a ?6?12/2 2 +== , j i a m F ?12?24+== 为一与时间无关的恒矢量，∴ 质点受恒力而运动。 F=(242+122)1/2=125N ，力与x 轴之间夹角为： '34265.0/?===arctg F arctgF x y α 3.4.2 质量为m 的质点在o-xy 平面内运动，质点的运动学方程为： j t b i t a r ?sin ?cos ωω+= ，a,b,ω为正常数，证明作用于质点的合力总指向原点。 证明：∵r j t b i t a dt r d a 222 2 )?sin ?cos (/ωωωω-=+-== r m a m F 2ω-==, ∴作用于质点的合力总指向原点。 3.4.4 桌面上叠放着两块木板，质量各为m 1 ,m 2,如图所示，m 2和桌面间的摩擦系数为μ2，m 1和m 2间的摩擦系数为μ1，问沿水平方向用多大的力才能把下面的木板抽出来。 解：以地为参考系，隔离m 1、m 2，其受力与运动情况如图所示， 其中，N 1'=N 1,f 1'=f 1=μ1N 1,f 2=μ2N 2，选图示坐标系o-xy ，对m 1,m 2分别应用牛顿二定律，有 02122222 11111 111=--=--=-=g m N N a m N N F g m N a m N μ μμ 解方程组，得 ()2221211211/m g m g m g m F a g a μμμμ---== 要把木板从下面抽出来，必须满足12a a >，即 g m g m g m g m F 12221211μμμμ>---()()g m m F 212 1++>∴μ μ 3.4.6在图示的装置中两物体的质量各为m 1,m 2，物体之间及物体与桌面间的摩擦系数都为μ，求在力F 的作用下两物体的加速度及绳内张力，不计滑轮和绳的质量及轴承摩擦，绳不可伸长。 m 1g f 1 N 1 a 1 a 2 x y
外贸函电复习题及答案Word版
二. 短语翻译 1． From English to Chinese 1) terms of payment 2) net weight 3) Bill of Lading 4) Country of origin 2. From Chinese to English 1) 供求 2）标题项下的货物 3）商会 4）共同努力 5）保兑信用证 6）会签 三. 句子翻译 1. 我们男士衬衫的包装为每件套一塑料袋，五打装一纸箱。内衬防潮纸，外打铁箍两道。 2. 因无直达班轮，请允许转船。 3．我们得悉上述货物的有关信用证即将开出。保证一收到贵方信用证，我们将尽早安排第一艘可以定得舱位的船只装运。 三. 信件翻译 敬启者： 你公司11月5日的报价单和尼龙女式运动成衣样品都已收到，谢谢。我公司对价格和品质均感满意，并乐意按你方报价单所提条件订购下列货物： 小号尼龙运动衣每打80美元成本加保险费加运费到伦敦价, 5打。 中号尼龙运动衣每打120美元成本加保险费加运费到伦敦价 7打。 大号尼龙运动衣每打160美元成本加保险费加运费到伦敦价 4打。 只有在满足12月15日前将货运到的条件下，我公司才订购上述尼龙运动衣。 我公司通常的付款条件是60天承兑交单。请告你公司是否同意这一条件。 ….谨上 二．翻译 短语翻译 1．支付条件 2.净重 3. 提单 4. 原产地 1. supply and demand 2. the captioned goods 3.the chamber of commerce 4.joint effort 5. confirmed L/C 6.countersign 句子翻译 1. Our Men’s Shirts are packed in poly bags, five dozen to a carton lined with damp-proof paper and secured with 2 iron straps outside. 2. As there is no direct steamer, please allow transshipment. 3. We have learned that the relative L/C for the above-mentioned goods will be opened immediately. You are assured that upon receipt of your L/C, we will arrange to ship by the first available steamer. 信件翻译（注意格式） Dear sirs We thank you for your quotation of Nov．5 and the samples of ready-made nylon women’s sports garments. We are satisfied with both the quality and price,and pleased to order the following goods according to the terms of your quotation： Small size women’s sports coat US＄80 per dozen CIF London 5 dozens . Medium size women’s sports coat US＄120 per dozen CIF London 7dozens. Large size women’s sports coat US＄160 per dozen CIF London 4dozens. We place the order with you for the above-mentioned goods subject to your delivery of the goods prior to December 15. Our normal term of payment is D/A after 60 days.Please let us know whether you agree to the terms of payment. Yours faithfully， 外贸函电试题库 Match