托福阅读真题3

托福阅读真题3

By the mid-nineteenth century,the term icebox had entered the American language,but icewas still only beginning to affect the diet of ordinary citizens in the United States.The ice tradegrew with the growth of cities.Ice was used in hotels,taverns,and hospitals,and by someforward-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,halfthe ice sold in New York,Philadelphia,and Baltimore,and one-third of that sold in Boston andChicago,went to families for their own use.This had become possible because a new householdconvenience,the icebox,a precursor of the modern refrigerator,had been invented.

Making an efficient icebox was not as easy as we might now suppose.In the early nineteenthcentury,the knowledge of the 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 icefrom melting was of course mistaken,for it was the melting of the ice that performed the cooling.Nevertheless,early efforts to economize ice included wrapping the ice in blankets,which kept theice from doing its job.Not until near the end of the nineteenth century did inventors achieve thedelicate 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 righttrack.He owned a farm about twenty miles outside the city of Washington,for which the villageof Georgetown was the market center.When he used an icebox of his own design to transport hisbutter to market,he found that customers would pass up the rapidly melting stuff in the tubs ofhis competitors to pay a premium price for his butter,still fresh and hard in neat,one-poundbricks.One advantage of his icebox,Moore explained,was that farmers would no longer have totravel to market at night in order to keep their produce cool.

5.The word it in line 5 refers to

(A)fresh meat

(B)the Civil War

(C)ice

(D)a refrigerator

6.According to the passage,which of the following was an obstacle to the development of the

icebox?

(A)Competition among the owners of refrigerated freight cars

(B)The lack of a network for the distribution of ice

(C)The use of insufficient insulation

(D)Inadequate understanding of physics

参考答案：CD