2014年4月托福考试模拟试卷及答案(第一套)_第3页

　11. The word toxic in paragraph 5 is closest in meaning to

　　experimented with ice making, and in l85l he was granted the first U.S. patent for mechanical refrigeration. In the same year, an Australian printer, James Harrison, built an ether refrigerator after noticing that when he cleaned his type with ether it became very cold as the ether evaporated. Five years later, Harrison introduced vapor-compression refrigeration to the brewing and meatpacking industries.

　　Brewing was the first industry in the United States to use mechanical refrigeration extensively, and in the 1 870s, commercial refrigeration was primarily directed at breweries. German-born Adolphus Busch was the first to use artificial refrigeration at his brewery in St. Louis. Before refrigeration, brewers stored their beer in caves, and production was constrained by the amount of available cave space. Brewing was strictly a local business, since beer was highly perishable and shipping it any distance would result in spoilage. Busch solved the storage problem with the commercial vapor-compression refrigerator. He solved he shipping problem with the newly invented refrigerated railcar, which was insulated with ice bunkers in each end. Air came in on the top, passed through the bunkers, and circulated through the car by gravity. In solving Busch’s spoilage and storage problems, refrigeration also revolutionized an entire industry. By 1891, nearly every brewery was equipped with mechanical refrigerating machines.

　　The refrigerators of today rely on the same basic principle of cooling caused by the rapid evaporation and expansion of gases. Until l929, refrigerators used toxic gases—ammonia, methyl chloride, and sulfur dioxide—as refrigerants. After those gases accidentally killed several people, chlorofluorocarbons (CFCs) became the standard refrigerant. However, they were found to be harmful to the earth’s ozone layer, so refrigerators now use a refrigerant called HF134a, which is less harmful to the ozone.

　　dense

　　poisonous

　　rare

　　expensive

　　12. Look at the four squares, A, B, C, and D, which indicate where the following sentence could be added to the passage. Where would the sentence best fit?

　　Gorrie’s basic principle of compressing a gas, and then sending it through radiating coils to cool it, is the one most often used in refrigerators today.

　　Scientists and inventors from around the world developed artificial refrigeration during the eighteenth and nineteenth centuries. A William Cullen demonstrated artificial refrigeration in Scotland in 1748, when he let ethyl ether boil into a partial vacuum. In 1805, American inventor Oliver Evans designed the first refrigeration machine that used vapor instead of liquid. B In 1842, physician John Gorrie used Evans’s design to create an air-cooling apparatus to treat yellow-fever patients in a Florida hospital. C Gorrie later left his medical practice and experimented with ice making, and in 1851 he was granted the first U.S. patent for mechanical refrigeration. D In the same year, an Australian printer, James Harrison, built an ether refrigerator after noticing that when he cleaned his type with ether it became very cold as the ether evaporated. Five years later, Harrison introduced vapor—compression refrigeration to the brewing and meatpacking industries.

　　13—14. An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

　　Methods of refrigeration have changed throughout history.

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　　●

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　　Answer Choiees

　　A refrigerator has an evaporator that makes the inside of the refrigerator cold.

　　People used to preserve food by packing it with ice or snow in cold storage areas.

　　Artificial refrigeration Was made possible by the compression and evaporation of a volatile substance.

　　William Cullen developed a method of artificial refrigeration in 1748.

　　Practical uses of vapor-compression refrigeration were introduced in the nineteenth century.

　　CFCs have not been used as refrigerants since they were found to damage the earth’s ozone layer.

　　15. According to the passage, how did Canadian English become a distinct variety of North American English?

　　Linguists noticed that Canadians spoke a unique dialect.

　　A large group of Loyalists settled in one region at the same time.

　　Growth of the middle class led to a standard school curriculum.

　　Canadians declared their language to be different from U.S. English.