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(半合成的) , 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 (monomers) link together in the setting or curing(硫化) 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 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

　　In today's world, insurance plays a vital role in the economic and social welfare of the entire population. The wish to guard against dangers to life and property is basic to human nature. By using various kinds of insurance, society has been able to reduce the effects of such hazards.

　　Nowhere is insurance more important than in the management of a business. In many instances, losses in a small firm can mean the difference between growth and failure, vitality and stagnation (停滯).Very few small businesses have even a portion of the financial resources available to larger enterprises. Frequently, they must operate on a very slight margin if they hope to stay in business. And thus, they are particularly sensitive to unexpected losses.

　　Without enough insurance, what happens to such a firm when the owner dies or is suddenly disabled? When a fire breaks out and destroys the firm's building or stock? When an employee is found to have stolen company funds? When a customer is awarded a liability judgment for an accident? Too often, the business is forced to the wall, its future operations drastically curbed; sometimes, it is damaged beyond repair, its ability to continue completely crushed.

　　Almost always, a small businessman would find it impossible to handle the full burden of his potential risk. The amount of money he would have to set aside to cover possible losses would leave him nothing, or almost nothing, to run his business with. If loss were to occur which he could repair by using his reserve fund, what assurance would he have that another loss—the same kind or different—might not occur next week, next month? But then he would have no reserve fund and little likelihood of staying in business at all.

　　26. This selection deals mainly with_______.

　　A. the relation between insurance and society

　　B. accidents and losses

　　C. business failures

　　D. the importance of insurance to business

　　27. In Paragraph 3, "forced to the wall" means "_______".

　　A. driven to despair B. staying in a strong position

　　C. doing well D. climbing up

　　28. The author thinks that_______.

　　A. accidents always happen

　　B. a businessman should take risks

　　C. businesses should have adequate insurance

　　D. insurance is a social welfare project

　　29. Adequate insurance will do all of the following EXCEPT that it will_______.

　　A. free some business funds B. add to benefits for employees

　　C. relieve some management problems D. provide for unexpected incidents

　　30. The word "curbed" in Paragraph 3 is nearest in meaning to_______.

　　A. checked B. advanced

　　C. expanded D. disturbed

　　26. D 27. A 28. C 29. B 30. A