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Plastics are materials which are softened by heat and set into lasting form when shaped in a mold. Some are natural; some are semisynthetic (半合成的), the result of chemical action on a natural substance; some are synthetic, built up from the constituents (成分) of oil or coal. All are based on the chemistry of carbon, with its capacity for forming chains. The molecules that compose them (monomers) link together in the setting or curing (加工) process to form chains (polymers), 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 call 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, have 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 cheap.
57. Which of the following groups of adjectives best concludes the characteristics of plastics?
A) Inexpensive, convenient and historic.
B) Disposable, rare and interesting.
C) Inexpensive, convenient and disposable.
D) Rare, beautiful and unbreakable.
58. According to the first paragraph, plastics can be classified into .
A) monomers and polymers
B) flexible plastics and inflexible plastics
C) thermoplastics and thermosetting plastics
D) natural plastics and synthetic plastics
59. When plastics were invented a hundred and twenty years ago, ______..
A) people found they were cold materials
B) their shapes were set permanent
C) people accepted them at once
D) they did not enjoy immediate popularity
60. Which of the following statements is NOT TRUE according to this passage?
A) There has been ups and downs in the development history of plastic technology.
B) Nowadays plastics help people to live a more convenient life in modern world.
C) Since plastic technology does not have a long history, there are no plastic antiques at all.
D) Collecting cheap but beautiful plastic antiques can be funny sometimes.
61. The word "sympathetic" in the last sentence of the second paragraph is closest to ______.
A) favorable B) pitiable C) easy D) harmless
