By the mid-nineteenth century, the “icebox” had entered the American language, but ice was

By the mid-nineteenth century, the “icebox” had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1861-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families of their own use. This had become possible because a new household convenience, the icebox, a precursors of modern refrigerator, had been invented.
Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of physics of heat, which was essential to a science of refrigeration, was rudimentary. The commonsense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the delicate balance of insulation and circulation needed for an efficient icebox.
But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium(奖金) price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.
【小题1】What does the passage mainly discuss?A．The influence of ice on the diet.B．The development of refrigeration.C．The transportation of goods to market.D．Sources of ice in the nineteenth century.【小题2】According to the passage, when did the word “icebox” become part of the language of the United States?A．in 1803B．sometime bore 1850C．during the civil warD．near the end of the nineteenth century.【小题3】The phrase “forward-looking” in line 3 is closest in meaning to .A．progressiveB．popularC．thriftyD．well-established【小题4】The author mentions “fish” in the passage because .A．many fish dealers also sold ice.B．fish was shipped in refrigerated freight cars.C．fish dealers were among the early commercial users of iceD．fish was not part of the ordinary person’s diet before the invention of the icebox.B

(答案→)B 解析：本文主要讲述的就是冰箱这一现时代的事物的发展过程。【小题1】B 主旨大意题。根据文章第一段最后一句This had become possible because a new household convenience, the icebox, a precursors of modern refrigerator, had been invented.说明本文主要就是关于冰箱的发展过程，故B正确。【小题2】B 细节题。根据文章第一句By the mid-nineteenth century, the “icebox” had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States.说明是在19世纪中叶“icebox”进入了英语，故B正确。【小题3】A 推理题。根据本句The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter.说明冰的贸易很流行，有一些有远见的人把冰用在了肉，鱼和黄油的保险方面，故该词是指不段前进的，向前发展的。故A正确。【小题4】C 细节题。根据The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter.说明鱼的保鲜也是在冰的商业用途之一，故C正确。

就是这个解释