小说搜索     点击排行榜   最新入库
首页 » 经典英文小说 » The Economy of Workshop Mainipulation » CHAPTER I. PLANS OF STUDYING.
选择底色: 选择字号:【大】【中】【小】
CHAPTER I. PLANS OF STUDYING.
关注小说网官方公众号(noveltingroom),原版名著免费领。
By examining the subject of applied1 mechanics and shop manipulation, a learner may see that the knowledge to be acquired by apprentices2 can be divided into two departments, that may be called general and special. General knowledge relating to tools, processes and operations, so far as their construction and action may be understood from general principles, and without special or experimental instruction. Special knowledge is that which [7] is based upon experiment, and can only be acquired by special, as distinguished4 from general sources.

To make this plainer, the laws of forces, the proportion of parts, strength of material, and so on, are subjects of general knowledge that may be acquired from books, and understood without the aid of an acquaintance with the technical conditions of either the mode of constructing or the manner of operating machines; but how to construct proper patterns for castings, or how the parts of machinery5 should be moulded, forged, or fitted, is special knowledge, and must have reference to particular cases. The proportions of pulleys, bearings, screws, or other regular details of machinery, may be learned from general rules and principles, but the hand skill that enters into the manufacture of these articles cannot be learned except by observation and experience. The general design, or the disposition6 of metal in machine-framing, can be to a great extent founded upon rules and constants that have general application; but, as in the case of wheels, the plans of moulding such machine frames are not governed by constant rules or performed in a uniform manner. Patterns of different kinds may be employed; moulds may be made in various ways, and at a greater and less expense; the metal can be mixed to produce a hard or a soft casting, a strong or a weak one; the conditions under which the metal is poured may govern the soundness or shrinkage,—things that are determined7 by special instead of general conditions.

The importance of a beginner learning to divide what he has to learn into these two departments of special and general, has the advantage of giving system to his plans, and pointing out that part of his education which must be acquired in the workshop and by practical experience. The time and opportunities which might be devoted8 to learning the technical manipulations of a foundry, for instance, would be improperly9 spent if devoted to metallurgic chemistry, because the latter may be studied apart from practical foundry manipulation, and without the opportunity of observing casting operations.

It may also be remarked that the special knowledge involved in applied mechanics is mainly to be gathered and retained by personal observation and memory, and that this part is the greater one; all the formul? relating to machine construction may be learned in a shorter time than is required to master and understand the operations which may be performed on an engine [8] lathe10. Hence first lessons, learned when the mind is interested and active, should as far as possible include whatever is special; in short, no opportunity of learning special manipulation should be lost. If a wheel pattern come under notice, examine the manure11 in which it is framed together, the amount of draught12, and how it is moulded, as well as to determine whether the teeth have true cycloidal curves.

Once, nearly all mechanical knowledge was of the class termed special, and shop manipulations were governed by empirical rules and the arbitrary opinions of the skilled; an apprentice3 entered a shop to learn a number of mysterious operations, which could not be defined upon principles, and only understood by special practice and experiment. The arrangement and proportions of mechanism13 were also determined by the opinions of the skilled, and like the manipulation of the shop, were often hid from the apprentice, and what he carried in his memory at the end of an apprenticeship14 was all that he had gained. The tendency of this was to elevate those who were the fortunate possessors of a strong natural capacity, and to depress the position of those less fortunate in the matter of mechanical "genius," as it was called. The ability to prepare proper designs, and to succeed in original plans, was attributed to a kind of intuitive faculty15 of the mind; in short, the mechanic arts were fifty years ago surrounded by a superstition16 of a different nature, but in its influences the same as superstition in other branches of knowledge.

But now all is changed: natural phenomena17 have been explained as being but the operation of regular laws; so has mechanical manipulation been explained as consisting in the application of general principles, not yet fully18 understood, but far enough, so that the apprentice may with a substantial education, good reasoning powers, and determined effort, force his way where once it had to be begged. The amount of special knowledge in mechanical manipulation, that which is irregular and modified by special conditions, is continually growing less as generalisation and improvement go on.

Another matter to be considered is that the engineering apprentice, in estimating what he will have to learn, must not lose sight of the fact that what qualifies an engineer of to-day will fall far short of the standard that another generation will fix, and of that period in which his practice will fall. This I mention because it will have much to do with the conceptions that a [9] learner will form of what he sees around him. To anticipate improvement and change is not only the highest power to which a mechanical engineer can hope to attain19, but is the key to his success.

By examining the history of great achievements in the mechanic arts, it will be seen that success has been mainly dependent upon predicting future wants, as well as upon an ability to supply such wants, and that the commercial value of mechanical improvements is often measured by conditions that the improvements themselves anticipate. The invention of machine-made drills, for example, was but a small matter; but the demand that has grown up since, and because of their existence, has rendered this improvement one of great value. Moulded bearings for shafts20 were also a trifling21 improvement when first made, but it has since influenced machine construction in America in a way that has given great importance to the invention.

It is generally useless and injudicious to either expect or to search after radical22 changes or sweeping23 improvements in machine manufacture or machine application, but it is important in learning how to construct and apply machinery, that the means of foreseeing what is to come in future should at the same time be considered. The attention of a learner can, for example, be directed to the division of labour, improvements in shop system, how and where commercial interests are influenced by machinery, what countries are likely to develop manufactures, the influence of steam-hammers on forging, the more extended use of steel when cheapened by improved processes for producing it, the division of mechanical industry into special branches, what kind of machinery may become staple24, such as shafts, pulleys, wheels, and so on. These things are mentioned at random25, to indicate what is meant by looking into the future as well as at the present.

Following this subject of future improvement farther, it may be assumed that an engineer who understands the application and operation of some special machine, the principles that govern its movements, the endurance of the wearing surfaces, the direction and measure of the strains, and who also understands the principles of the distribution of material, arrangement, and proportions,—that such an engineer will be able to construct machines, the plans of which will not be materially departed from so long as the nature of the operations to which [10] the machines are applied remain the same.

A proof of this proposition is furnished in the case of standard machine tools for metal-cutting, a class of machinery that for many years past has received the most thorough attention at the hands of our best mechanical engineers.

Standard tools for turning, drilling, planing, boring, and so on, have been changed but little during twenty years past, and are likely to remain quite the same in future. A lathe or a planing-machine made by a first-class establishment twenty years ago has, in many cases, the same capacity, and is worth nearly as much in value at the present time as machine tools of modern construction—a test that more than any other determines their comparative efficiency and the true value of the improvements that have been made. The plans of the framing for machine tools have been altered, and many improvements in details have been added; yet, upon the whole, it is safe to assume, as before said, that standard tools for metal-cutting have reached a state of improvement that precludes26 any radical changes in future, so long as the operations in metal-cutting remain the same.

This state of improvement which has been reached in machine-tool manufacture, is not only the result of the skill expended27 on such tools, but because as a notable exception they are the agents of their own production; that is, machine tools produce machine tools, and a maker28 should certainly become skilled in the construction of implements29 which he employs continually in his own business. This peculiarity30 of machine-tool manufactures is often overlooked by engineers, and unfair comparisons made between machines of this class and those directed to wood conversion31 and other manufacturing processes, which machinists, as a rule, do not understand.

Noting the causes and conditions which have led to this perfection in machine-tool manufacture, and how far they apply in the case of other classes of machinery, will in a measure indicate the probable improvements and changes that the future will produce.

The functions and adaptations of machinery constitute, as already explained, the science of mechanical engineering. The functions of a machine are a foundation on which its plans are based; hence machine functions and machine effect are matters to which the attention of an apprentice should first [11] be directed.

In the class of mechanical knowledge that has been defined as general, construction comes in the third place: first, machine functions; next, plans or adaptation of machines; and third, the manner of constructing machines. This should be the order of study pursued in learning mechanical manipulation. Instead of studying how drilling-machines, planing-machines or lathes32 are arranged, and next plans of constructing them, and then the principles of their operation, which is the usual course, the learner should reverse the order, studying, first, drilling, planing, and turning as operations; next, the adaptation of tools for the purposes; and third, plans of constructing such tools.

Applied to steam-engines, the same rule holds good. Steam, as a motive33 agent, should first be studied, then the operation of steam machinery, and finally the construction of steam-engines. This is a rule that may not apply in all cases, but the exceptions are few.

To follow the same chain of reasoning still farther, and to show what may be gained by method and system in learning mechanics, it may be assumed that machine functions consist in the application of power, and therefore power should be first studied; of this there can be but one opinion. The learner who sets out to master even the elementary principles of mechanics without first having formed a true conception of power as an element, is in a measure wasting his time and squandering34 his efforts.

Any truth in mechanics, even the action of the "mechanical powers" before alluded35 to, is received with an air of mystery, unless the nature of power is first understood. Practical demonstration36 a hundred times repeated does not create a conviction of truth in mechanical propositions, unless the principles of operation are understood.

An apprentice may learn that power is not increased or diminished by being transmitted through a train of wheels which change both speed and force, and he may believe the proposition without having a "conviction" of its truth. He must first learn to regard power as a constant and indestructible element—something that may be weighed, measured, and transmitted, but not created or destroyed by mechanism; then the nature of the mechanism may be understood, but not before.

To obtain a true understanding of the nature of power is by no means the difficulty for a beginner that is generally supposed [12]; and when once reached, the truth will break upon the mind like a sudden discovery, and ever afterwards be associated with mechanism and motion whenever seen. The learner will afterwards find himself analysing the flow of water, the traffic in the streets, the movement of ships and trains; even the act of walking will become a manifestation37 of power, all clear and intelligible38, without that air of mystery that is otherwise inseparable from the phenomena of motion. If the learner will go on farther, and study the connection between heat and force, the mechanical equivalent of heat when developed into force and motion, and the reconversion of power into heat, he will have commenced at the base of what must constitute a thorough knowledge of mechanics, without which he will have to continually proceed under difficulties.

I am well aware of the popular opinion that such subjects are too abstruse39 to be understood by practical mechanics—an assumption that is founded mainly in the fact that the subject of heat and motion are not generally studied, and have been too recently demonstrated in a scientific way to command confidence and attention; but the subject is really no more difficult to understand in an elementary sense than that of the relation between movement and force illustrated40 in the "mechanical powers" of school-books, which no apprentice ever did or ever will understand, except by first studying the principles of force and motion, independent of mechanical agents, such as screws, levers, wedges, and so on.

It is to be regretted that there have not been books especially prepared to instruct mechanical students in the relations between heat, force, motion, and practical mechanism. The subject is, of course, treated at great length in modern scientific works, but is not connected with the operations of machinery in a way to be easily understood by beginners. A treatise41 on the subject, called "The Correlation42 and Conservation of Forces," published by D. Appleton & Co. of New York, is perhaps as good a book on the subject as can at this time be referred to. The work contains papers contributed by Professors Carpenter, Grove43, Helmholtz, Faraday, and others, and has the advantage of arrangement in short sections, that compass the subject without making it tedious.

In respect to books and reading, the apprentice should supply himself with references. A single book, and the best one that can be obtained on each of the different branches of engineering, is [13] enough to begin with. A pocket-book for reference, such as Molesworth's or Nystrom's, is of use, and should always be at hand. For general reading, nothing compares with the scientific and technical journals, which are now so replete44 with all kinds of information. Beside noting the present progress of engineering industry in all parts of the world, they contain nearly all besides that a learner will require.

It will be found that information of improvements and mechanical progress that a learner may gather from serial45 publications can always be exchanged for special knowledge in his intercourse46 with skilled workmen, who have not the opportunity or means of reading for themselves; and what an apprentice may read and learn in an hour can often be "exchanged" for experimental knowledge that has cost years to acquire.

(1.) Into what two divisions can a knowledge of constructive47 mechanics be divided?—(2.) Give an example of your own to distinguish between special and general knowledge.—(3.) In what manner is special knowledge mostly acquired?—(4.) What has been the effect of scientific investigations48 upon special knowledge?—(5.) What is meant by the division of labour?—(6.) Why have engineering tools been less changed than most other kinds of machinery during twenty years past?—(7.) What is meant by machine functions; adaptation; construction?—(8.) Why has the name "mechanical powers" been applied to screws, levers, wedges, and so on?—(9.) Can power be conceived of as an element or principle, independent of mechanism?

点击收听单词发音收听单词发音  

1 applied Tz2zXA     
adj.应用的;v.应用,适用
参考例句:
  • She plans to take a course in applied linguistics.她打算学习应用语言学课程。
  • This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。
2 apprentices e0646768af2b65d716a2024e19b5f15e     
学徒,徒弟( apprentice的名词复数 )
参考例句:
  • They were mere apprentices to piracy. 他们干海盗仅仅是嫩角儿。
  • He has two good apprentices working with him. 他身边有两个好徒弟。
3 apprentice 0vFzq     
n.学徒,徒弟
参考例句:
  • My son is an apprentice in a furniture maker's workshop.我的儿子在一家家具厂做学徒。
  • The apprentice is not yet out of his time.这徒工还没有出徒。
4 distinguished wu9z3v     
adj.卓越的,杰出的,著名的
参考例句:
  • Elephants are distinguished from other animals by their long noses.大象以其长长的鼻子显示出与其他动物的不同。
  • A banquet was given in honor of the distinguished guests.宴会是为了向贵宾们致敬而举行的。
5 machinery CAdxb     
n.(总称)机械,机器;机构
参考例句:
  • Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗?
  • Machinery ought to be well maintained all the time.机器应该随时注意维护。
6 disposition GljzO     
n.性情,性格;意向,倾向;排列,部署
参考例句:
  • He has made a good disposition of his property.他已对财产作了妥善处理。
  • He has a cheerful disposition.他性情开朗。
7 determined duszmP     
adj.坚定的;有决心的
参考例句:
  • I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
  • He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
8 devoted xu9zka     
adj.忠诚的,忠实的,热心的,献身于...的
参考例句:
  • He devoted his life to the educational cause of the motherland.他为祖国的教育事业贡献了一生。
  • We devoted a lengthy and full discussion to this topic.我们对这个题目进行了长时间的充分讨论。
9 improperly 1e83f257ea7e5892de2e5f2de8b00e7b     
不正确地,不适当地
参考例句:
  • Of course it was acting improperly. 这样做就是不对嘛!
  • He is trying to improperly influence a witness. 他在试图误导证人。
10 lathe Bk2yG     
n.车床,陶器,镟床
参考例句:
  • Gradually she learned to operate a lathe.她慢慢地学会了开车床。
  • That lathe went out of order at times.那台车床有时发生故障。
11 manure R7Yzr     
n.粪,肥,肥粒;vt.施肥
参考例句:
  • The farmers were distributing manure over the field.农民们正在田间施肥。
  • The farmers used manure to keep up the fertility of their land.农夫们用粪保持其土质的肥沃。
12 draught 7uyzIH     
n.拉,牵引,拖;一网(饮,吸,阵);顿服药量,通风;v.起草,设计
参考例句:
  • He emptied his glass at one draught.他将杯中物一饮而尽。
  • It's a pity the room has no north window and you don't get a draught.可惜这房间没北窗,没有过堂风。
13 mechanism zCWxr     
n.机械装置;机构,结构
参考例句:
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
14 apprenticeship 4NLyv     
n.学徒身份;学徒期
参考例句:
  • She was in the second year of her apprenticeship as a carpenter. 她当木工学徒已是第二年了。
  • He served his apprenticeship with Bob. 他跟鲍勃当学徒。
15 faculty HhkzK     
n.才能;学院,系;(学院或系的)全体教学人员
参考例句:
  • He has a great faculty for learning foreign languages.他有学习外语的天赋。
  • He has the faculty of saying the right thing at the right time.他有在恰当的时候说恰当的话的才智。
16 superstition VHbzg     
n.迷信,迷信行为
参考例句:
  • It's a common superstition that black cats are unlucky.认为黑猫不吉祥是一种很普遍的迷信。
  • Superstition results from ignorance.迷信产生于无知。
17 phenomena 8N9xp     
n.现象
参考例句:
  • Ade couldn't relate the phenomena with any theory he knew.艾德无法用他所知道的任何理论来解释这种现象。
  • The object of these experiments was to find the connection,if any,between the two phenomena.这些实验的目的就是探索这两种现象之间的联系,如果存在着任何联系的话。
18 fully Gfuzd     
adv.完全地,全部地,彻底地;充分地
参考例句:
  • The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
19 attain HvYzX     
vt.达到,获得,完成
参考例句:
  • I used the scientific method to attain this end. 我用科学的方法来达到这一目的。
  • His painstaking to attain his goal in life is praiseworthy. 他为实现人生目标所下的苦功是值得称赞的。
20 shafts 8a8cb796b94a20edda1c592a21399c6b     
n.轴( shaft的名词复数 );(箭、高尔夫球棒等的)杆;通风井;一阵(疼痛、害怕等)
参考例句:
  • He deliberately jerked the shafts to rock him a bit. 他故意的上下颠动车把,摇这个老猴子几下。 来自汉英文学 - 骆驼祥子
  • Shafts were sunk, with tunnels dug laterally. 竖井已经打下,并且挖有横向矿道。 来自辞典例句
21 trifling SJwzX     
adj.微不足道的;没什么价值的
参考例句:
  • They quarreled over a trifling matter.他们为这种微不足道的事情争吵。
  • So far Europe has no doubt, gained a real conveniency,though surely a very trifling one.直到现在为止,欧洲无疑地已经获得了实在的便利,不过那确是一种微不足道的便利。
22 radical hA8zu     
n.激进份子,原子团,根号;adj.根本的,激进的,彻底的
参考例句:
  • The patient got a radical cure in the hospital.病人在医院得到了根治。
  • She is radical in her demands.她的要求十分偏激。
23 sweeping ihCzZ4     
adj.范围广大的,一扫无遗的
参考例句:
  • The citizens voted for sweeping reforms.公民投票支持全面的改革。
  • Can you hear the wind sweeping through the branches?你能听到风掠过树枝的声音吗?
24 staple fGkze     
n.主要产物,常用品,主要要素,原料,订书钉,钩环;adj.主要的,重要的;vt.分类
参考例句:
  • Tea is the staple crop here.本地产品以茶叶为大宗。
  • Potatoes are the staple of their diet.土豆是他们的主要食品。
25 random HT9xd     
adj.随机的;任意的;n.偶然的(或随便的)行动
参考例句:
  • The list is arranged in a random order.名单排列不分先后。
  • On random inspection the meat was found to be bad.经抽查,发现肉变质了。
26 precludes a6099ad5ef93a1df2eb33804a8db6373     
v.阻止( preclude的第三人称单数 );排除;妨碍;使…行不通
参考例句:
  • Lack of time precludes any further discussion. 由于时间不足,不可能进行深入的讨论。
  • The surface reactivity of many nonblack fillers generally precludes strong bonding with this type of matrix. 许多非碳黑填料的表面反应性一般阻碍与该种基质形成牢固的粘结。 来自辞典例句
27 expended 39b2ea06557590ef53e0148a487bc107     
v.花费( expend的过去式和过去分词 );使用(钱等)做某事;用光;耗尽
参考例句:
  • She expended all her efforts on the care of home and children. 她把所有精力都花在料理家务和照顾孩子上。
  • The enemy had expended all their ammunition. 敌人已耗尽所有的弹药。 来自《简明英汉词典》
28 maker DALxN     
n.制造者,制造商
参考例句:
  • He is a trouble maker,You must be distant with him.他是个捣蛋鬼,你不要跟他在一起。
  • A cabinet maker must be a master craftsman.家具木工必须是技艺高超的手艺人。
29 implements 37371cb8af481bf82a7ea3324d81affc     
n.工具( implement的名词复数 );家具;手段;[法律]履行(契约等)v.实现( implement的第三人称单数 );执行;贯彻;使生效
参考例句:
  • Primitive man hunted wild animals with crude stone implements. 原始社会的人用粗糙的石器猎取野兽。 来自《现代汉英综合大词典》
  • They ordered quantities of farm implements. 他们订购了大量农具。 来自《现代汉英综合大词典》
30 peculiarity GiWyp     
n.独特性,特色;特殊的东西;怪癖
参考例句:
  • Each country has its own peculiarity.每个国家都有自己的独特之处。
  • The peculiarity of this shop is its day and nigth service.这家商店的特点是昼夜服务。
31 conversion UZPyI     
n.转化,转换,转变
参考例句:
  • He underwent quite a conversion.他彻底变了。
  • Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。
32 lathes cd4be0c134cfc2d344542ceda5ac462c     
车床( lathe的名词复数 )
参考例句:
  • They showed keen interest in the various lathes on exhibition. 他们对展出中的各类车床表现出了浓厚的兴趣。
  • To automate the control process of the lathes has become very easy today. 使机床的控制过程自动化现已变得很容易了。
33 motive GFzxz     
n.动机,目的;adv.发动的,运动的
参考例句:
  • The police could not find a motive for the murder.警察不能找到谋杀的动机。
  • He had some motive in telling this fable.他讲这寓言故事是有用意的。
34 squandering 2145a6d587f3ec891a8ca0e1514f9735     
v.(指钱,财产等)浪费,乱花( squander的现在分词 )
参考例句:
  • You're faced with ending it all, of squandering what was given. 把到手的东西就这样随随便便弄掉。 来自辞典例句
  • I see all this potential And I see squandering. 你们的潜力都被浪费了。 来自互联网
35 alluded 69f7a8b0f2e374aaf5d0965af46948e7     
提及,暗指( allude的过去式和过去分词 )
参考例句:
  • In your remarks you alluded to a certain sinister design. 在你的谈话中,你提到了某个阴谋。
  • She also alluded to her rival's past marital troubles. 她还影射了对手过去的婚姻问题。
36 demonstration 9waxo     
n.表明,示范,论证,示威
参考例句:
  • His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
  • He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。
37 manifestation 0RCz6     
n.表现形式;表明;现象
参考例句:
  • Her smile is a manifestation of joy.她的微笑是她快乐的表现。
  • What we call mass is only another manifestation of energy.我们称之为质量的东西只是能量的另一种表现形态。
38 intelligible rbBzT     
adj.可理解的,明白易懂的,清楚的
参考例句:
  • This report would be intelligible only to an expert in computing.只有计算机运算专家才能看懂这份报告。
  • His argument was barely intelligible.他的论点不易理解。
39 abstruse SIcyT     
adj.深奥的,难解的
参考例句:
  • Einstein's theory of relativity is very abstruse.爱因斯坦的相对论非常难懂。
  • The professor's lectures were so abstruse that students tended to avoid them.该教授的课程太深奥了,学生们纷纷躲避他的课。
40 illustrated 2a891807ad5907f0499171bb879a36aa     
adj. 有插图的,列举的 动词illustrate的过去式和过去分词
参考例句:
  • His lecture was illustrated with slides taken during the expedition. 他在讲演中使用了探险时拍摄到的幻灯片。
  • The manufacturing Methods: Will be illustrated in the next chapter. 制作方法将在下一章说明。
41 treatise rpWyx     
n.专著;(专题)论文
参考例句:
  • The doctor wrote a treatise on alcoholism.那位医生写了一篇关于酗酒问题的论文。
  • This is not a treatise on statistical theory.这不是一篇有关统计理论的论文。
42 correlation Rogzg     
n.相互关系,相关,关连
参考例句:
  • The second group of measurements had a high correlation with the first.第二组测量数据与第一组高度相关。
  • A high correlation exists in America between education and economic position.教育和经济地位在美国有极密切的关系。
43 grove v5wyy     
n.林子,小树林,园林
参考例句:
  • On top of the hill was a grove of tall trees.山顶上一片高大的树林。
  • The scent of lemons filled the grove.柠檬香味充满了小树林。
44 replete BBBzd     
adj.饱满的,塞满的;n.贮蜜蚁
参考例句:
  • He was replete with food and drink.他吃喝得饱饱的。
  • This immense space may be replete with happiness and glory.这巨大的空间可能充满了幸福和光荣。
45 serial 0zuw2     
n.连本影片,连本电视节目;adj.连续的
参考例句:
  • A new serial is starting on television tonight.今晚电视开播一部新的电视连续剧。
  • Can you account for the serial failures in our experiment?你能解释我们实验屡屡失败的原因吗?
46 intercourse NbMzU     
n.性交;交流,交往,交际
参考例句:
  • The magazine becomes a cultural medium of intercourse between the two peoples.该杂志成为两民族间文化交流的媒介。
  • There was close intercourse between them.他们过往很密。
47 constructive AZDyr     
adj.建设的,建设性的
参考例句:
  • We welcome constructive criticism.我们乐意接受有建设性的批评。
  • He is beginning to deal with his anger in a constructive way.他开始用建设性的方法处理自己的怒气。
48 investigations 02de25420938593f7db7bd4052010b32     
(正式的)调查( investigation的名词复数 ); 侦查; 科学研究; 学术研究
参考例句:
  • His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查,但没有发现什么。
  • He often sent them out to make investigations. 他常常派他们出去作调查。


欢迎访问英文小说网

©英文小说网 2005-2010

有任何问题,请给我们留言,管理员邮箱:[email protected]  站长QQ :点击发送消息和我们联系56065533