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bakelite雅思解析答案分享

2023-06-25 10:57:52 來源:中國教育在線

在備考雅思的時候其中劍橋雅思資料一定要好好利用起來,bakelite就是劍橋雅思中的其中一篇閱讀,下面我就和大家分享下bakelite雅思解析答案。

bakelite雅思原文以及解析答案

原文:

BAKELITE

The birth of modern plastics

In 1907,Leo Hendrick Baekeland,a Belgian scientist working in New York,discovered and patented a revolutionary new synthetic material.His invention,which he named‘Bakelite,’was of enormous technological importance,and effectively launched the modern plastics industry.

The term‘plastic’comes from the Greek plassein,meaning‘to mould’.Some plastics are derived from natural sources,some are semi-synthetic(the result of chemical action on a natural substance),and some are entirely synthetic,that is,chemically engineered from the constituents of coal or oil.Some are‘thermoplastic’,which means that,like candlewax,they melt when heated and can then be reshaped.Others are‘thermosetting’:like eggs,they cannot revert to their original viscous state,and their shape is thus fixed for ever.Bakelite had the distinction of being the first totally synthetic thermosetting plastic.

The history of today’s plastics begins with the discovery of a series of semi-synthetic thermoplastic materials in the mid-nineteenth century.The impetus behind the development of these early plastics was generated by a number of factors—immense technological progress in the domain of chemistry,coupled with wider cultural changes,and the pragmatic need to find acceptable substitutes for dwindling supplies of‘luxury’materials such as tortoiseshell and ivory.

Baekeland’s interest in plastics began in 1885 when,as a young chemistry student in Belgium,he embarked on research into phenolic resins,the group of sticky substances produced when phenol(carbolic acid)combines with an aldehyde(a volatile fluid similar to alcohol).He soon abandoned the subject,however,only returning to it some years later.By 1905 he was a wealthy New Yorker,having recently made his fortune with the invention of a new photographic paper.While Baekeland had been busily amassing dollars,some advances had been made in the development of plastics.The years 1899 and 1900 had seen the patenting of the first semi-synthetic thermosetting material that could be manufactured on an industrial scale.In purely scientific terms,Baekeland’s major contribution to the field is not so much the actual discovery of the material to which he gave his name,but rather the method by which a reaction between phenol and formaldehyde could be controlled,thus making possible its preparation on a commercial basis.On 13 July 1907,Baekeland took out his famous patent describing this preparation,the essential features of which are still in use today.

The original patent outlined a three-stage process,in which phenol and formaldehyde(from wood or coal)were initially combined under vacuum inside a large egg-shaped kettle.The result was a resin known as Novalak which became soluble and malleable when heated.The resin was allowed to cool in shallow trays until it hardened,and then broken up and ground into powder.Other substances were then introduced:including fillers,such as woodflour,asbestos or cotton,which increase strength and moisture resistance,catalysts(substances to speed up the reaction between two chemicals without joining to either)and hexa,a compound of ammonia and formaldehyde which supplied the additional formaldehyde necessary to form a thermosetting resin.This resin was then left to cool and harden,and ground up a second time.The resulting granular powder was raw Bakelite,ready to be made into a vast range of manufactured objects.In the last stage,the heated Bakelite was poured into a hollow mould of the required shape and subjected to extreme heat and pressure,thereby‘setting’its form for life.

The design of Bakelite objects,everything from earrings to television sets,was governed to a large extent by the technical requirements of the molding process.The object could not be designed so that it was locked into the mould and therefore difficult to extract.A common general rule was that objects should taper towards the deepest part of the mould,and if necessary the product was molded in separate pieces.Moulds had to be carefully designed so that the molten Bakelite would flow evenly and completely into the mould.Sharp corners proved impractical and were thus avoided,giving rise to the smooth,‘streamlined’style popular in the 1930s.The thickness of the walls of the mould was also crucial:thick walls took longer to cool and harden,a factor which had to be considered by the designer in order to make the most efficient use of machines.

Baekeland’s invention,although treated with disdain in its early years,went on to enjoy an unparalleled popularity which lasted throughout the first half of the twentieth century.It became the wonder product of the new world of industrials expansion—‘the material of a thousand uses’.Being both non-porous and heat-resistant,Bakelite kitchen goods were promoted as being germ-free and sterilisable.Electrical manufacturers seized on its insulating properties,and consumers everywhere relished its dazzling array of shades,delighted that they were now,at last,no longer restricted to the wood tones and drab browns of the preplastic era.It then fell from favour again during the 1950s,and was despised and destroyed in vast quantities.Recently,however,it has been experiencing something of a renaissance,with renewed demand for original Bakelite objects in the collectors’marketplace,and museums,societies and dedicated individuals once again appreciating the style and originality of this innovative material.

Questions 1-3

Complete the summary.

Choose ONE WORD ONLY from the passage for each answer.

Write your answers in boxes 1-3 on your answer sheet.

Some plastics behave in a similar way to 1………in that they melt under heat and can be moulded into new forms.Bakelite was unique because it was the first material to be both entirely 2………in origin,and thermosetting.

There were several reasons for the research into plastics in the nineteenth century,among them the great advances that had been made in the field of 3…………and the search for alternatives to natural resources like ivory.

Questions 4-8

Complete the flow-chart.

Choose ONE WORD ONLY from the passage for each answer.

Write your answers in boxes 4-8 on your answer sheet.

The Production of Bakelite

Questions 9 and 10

Choose TWO letters A-E.

Write your answers in boxes 9 and 10 on your answer sheet.

NB Your answers may be given in either order.

Which TWO of the following factors influencing the design of Bakelite objects are mentioned in the text?

A the function which the object would serve

B the ease with which the resin could fill the mould

C the facility with which the object could be removed from the mould

D the limitations of the materials used to manufacture the mould

E the fashionable styles of the period

Questions 11-13

Do the following statements agree with the information given in Reading Passage 1?

In boxes 11-13 on your answer sheet,write

TRUE if the statement agrees with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

11 Modern-day plastic preparation is based on the same principles as that patented in 1907.

12 Bakelite was immediately welcomed as a practical and versatile material.

13 Bakelite was only available in a limited range of colours.

答案解析:

Question 1

答案:candlewax

關(guān)鍵詞:similar/melt under heat

定位原文:第2段倒數(shù)第2句“...like candlewax,they melt when heated...”

解題思路:只要能夠在第二段中找到定位詞melt和heated,很快就能夠找到similar的同義詞like。因此答案應(yīng)該選擇candlewax。

Question 2

答案:synthetic

關(guān)鍵詞:bakelite/both...and.../themosetting

定位原文:第2段最后1句“Bakelite had the distinction of being…”

解題思路:distinction和first對應(yīng)題目中的unique,而thermoseting一詞前面只有synthetic這個詞可以選擇,即使不認(rèn)識,也可以填上去。

Question 3

答案:chemistry

關(guān)鍵詞:the nineteenth century/advances/field/ivory

定位原文:第3段第2句“The impetus…”

解題思路:選用nineteenth century和ivory兩個特殊詞找到答案定位,然后再仔細(xì)尋找great advances的對應(yīng)詞immense technological progress,隨后馬上可以看到field的對應(yīng)詞domain。因此這道題目應(yīng)該填chemistry。

Question 4

答案:Novalak

關(guān)鍵詞:avoid overcrowded centre

定位原文:D段最后1句“Instead…”

解題思路:instead是一個轉(zhuǎn)折連接詞,后面的觀點與前者剛好相反。上一句說pushing everyone into the city centre was not the best approach,剛好證明我們應(yīng)該避免造成一個過度擁擠的市中心。

Question 5

答案:fillers

關(guān)鍵詞:cotton/asbestos/catalysts

定位原文:第5段第4句“Other…”

解題思路:此處需要注意答案并不是woodflour,因為文中說fillers such as woodflour,asbestos or cotton,后三者是作者舉出的filler的具體例子,故不選。

Question 6

答案:hexa

關(guān)鍵詞:ammonia/formaldehyde

定位原文:第5段第4句的后半句“hexa,a compound…”

解題思路:此題目位置稍有顛倒,但是只要明白compound是混合物的意思就不難得到答案是hexa。

Question 7

答案:raw

關(guān)鍵詞:resin/cool/harden/break up/powder/bakelite

定位原文:第5段第5句“This resin…”

解題思路:第五段先找到cool和harden,很快看到Bakelite,前面的詞是raw。

Question 8

答案:pressure

關(guān)鍵詞:mould/intense heat/cool

定位原文:第5段最后1句“In the last stage…”

解題思路:extreme和intense屬于同義表達,空處和intense heat形成并列關(guān)系,答案很容易得出是pressure。

Question 9&Question 10

答案:B C

關(guān)鍵詞:design/Bakelite

定位原文:第6段第2句“The object…”第6段第4句“Moulds had to be…”

解題思路:第2句對應(yīng)C選項,could not locked into和題目的remove from屬于同義表達;第4句對應(yīng)B選項,fill和flow completely into也屬于同義表達。

Question 11

答案:TRUE

關(guān)鍵詞:based on/the same

定位原文:第1段第2句和第4段最后1句

解題思路:文中l(wèi)aunch一詞實際上指的是1907年獲得專利的技術(shù)開啟了現(xiàn)代塑料工業(yè)的大門。所以答案應(yīng)該是TRUE。這一點在最后一段中也能得到印證。

Question 12

答案:FALSE

關(guān)鍵詞:welcome

定位原文:第7段第1句和倒數(shù)第2句

解題思路:文中明確提到在其剛剛誕生的時候,酚醛塑料頗為大眾所不屑,并不是立即就受到歡迎。下面的文章又提到it then fell from favour again during the 1950s.immediately一詞過于絕對,一般在題目中出現(xiàn)該詞選FALSE。

Question 13

答案:FALSE

關(guān)鍵詞:colours

定位原文:第7段第4句“...delighted that they were now,at last,no longer restricted to the wood tones and drab browns of the preplastic era.”

解題思路:這句話告訴我們在塑料發(fā)展的初級階段,人們只能買到木色和棕色的產(chǎn)品,但是隨著技術(shù)的進步,人們不再限于這兩種單調(diào)的顏色了。only一詞過于絕對,一般在題目中出現(xiàn)了該詞選FALSE。

以上就是bakelite雅思解析答案的分享,大家不僅知道了答案,同時也需要明白為什么是這個答案,直至能夠?qū)⒋纹喿x完全吃透。

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