Plastics are materials which are softened by heat and set into lasting form when shaped in a mold. Some are natural; some are semi-synthetic , the result of chemical action on natural substance; some are synthetic, built up from the constituents of oil or coal. All are based on the chemistry of carbon, with its capacity for forming chains. The molecules that compose them link together in the setting or curing(硫化) process to form chains , which give plastics their flexible strength. Some plastics retain their ability to be softened and reshaped; like wax, they are thermoplastic. Others set permanently in the shapes they are given by heat and pressure; like eggs, they are thermosetting.
From industrial beginnings in the nineteenth century, plastics have struggled through a hundred and twenty years of glory, failure, disrepute and suspicion on the slow road to public acceptance. Now, at last, one can positively say that plastics are appreciated and enjoyed for what they are; that they make modern life richer, more comfortable and convenient, and also more fun. Plastics are warm materials, sympathetic to the human touch, and their transformation into things that come into contact with human beings is entirely appropriate.
The fact that there are plastic antiques comes as a shock to most people. How can a material that seems so essentially twentieth century, and one that is so much associated with cheap, disposable products, has a history at all? It is a young technology, and a great part of the fun of collecting plastics is that beautiful pieces of historical interest can still be found very cheaply.
21. The word sympathetic in Paragraph 2 most probably means_______.
A. harmful B. agreeable
C. pitiful D. sorry
22. It can be concluded from this passage that_______.
A. plastics are synthetic materials
B. plastics won public acceptance 120 years ago
C. plastics are very harmful in modern life
D. plastics are cheap as antiques
23. Which of the following is essential to create any type of plastics? A. Carbon. B. Eggs.
C. Oil. D. Coal.
24. Plastics that harden into permanent shapes are called_______.
A. chained B. thermoplastic
C. synthetic D. thermosetting
25. Which of the following is the best title for the passage?
A. The Importance of Plastics in the Nineteenth Century.
B. Why People Are Suspicious of Plastics.
C. The Development of Plastics as a Modern Material.
D. How Plastics Are Manufactured.
21. B 22. D 23. A 24. D 25. C
新概念英语第一册 Lesson 61:A bad cold
新概念英语第一册 Lesson 97:A small blue case
新概念英语第一册 Lesson 79:Carol’s shopping list
新概念英语第一册 Lesson 83:Going on holiday
新概念英语第一册 Lesson 109:A good idea
新概念英语第一册 Lesson 75:Uncomfortable shoes
新概念英语第一册 Lesson 47:A cup of coffee
新概念英语第一册 Lesson 117: Tommy’s breakfast
新概念英语第一册 Lesson 137:A pleasant dream
新概念英语第一册 Lesson 63:Thank you,doctor
新概念英语第一册 Lesson 73:The way to King Street
新概念英语第一册 Lesson 107:It’s too small
新概念英语第一册 Lesson 121:The man in the hat
新概念英语第一册 Lesson 71:He’s awful
新概念英语第一册 Lesson 119:A true story
新概念英语第一册 Lesson 53:An interesting climate
新概念英语第一册 Lesson 93:Our new neighbour
新概念英语第一册 Lesson 43:Hurry up
新概念英语第一册 Lesson 87:A car crash
新概念英语第一册 Lesson 49:At the butcher’s
新概念英语第一册 Lesson 133:Sensational news
新概念英语第一册 Lesson 91:Poor Ian
新概念英语第一册 Lesson 85:Pairs in the spring
新概念英语第一册 Lesson 57:An unusual day
新概念英语第一册 Lesson 65:Not a baby
新概念英语第一册 Lesson 111:The most expensive model
新概念英语第一册 Lesson 39:Don’t drop it
新概念英语第一册 Lesson 77:Terrible toothache
新概念英语第一册 Lesson 103:The French test
新概念英语第一册 Lesson 89:For sale
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