首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect t
By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect t
admin
2010-09-25
77
问题
By the mid-nineteenth century, the term "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(酒馆), 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 of the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern fridge, had been invented.
Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary(未发展的). The commonsense notion that the best icebox was one that prevented the ice from 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 up 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, and 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 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.
What was essential to a science of refrigeration ac. cording to the passage?
选项
答案
Knowledge of the physics of heat.
解析
由题干关键词a science of refrigeration定位到原文第二段第二句话,...the knowledge of the physics of heat, which was essential to a science of refrigeration直接给出了问题的答案。
转载请注明原文地址:https://kaotiyun.com/show/xyz7777K
0
大学英语六级
相关试题推荐
Emotionsaredefinedasstrong,relativelyuncontrolledfeelingsthataffectourbehavior.Everyoneexperiencesawiderangeof
A、Arthistory.B、Elementaryeducation.C、Americanliterature.D、Psychology.B细节辨别题对话中双方的专业都提到了,海伦问男士的专业是否也是基础教育,由此可以判断她是学基础教育的。
Longbeforethefirst【B1】______arrivedinAmerican,astrangelookinganimallivedonthewestern【B2】______.Itlookedsomewha
Longbeforethefirst【B1】______arrivedinAmerican,astrangelookinganimallivedonthewestern【B2】______.Itlookedsomewha
Thecommandersaidtohistroopsthat___________________________(在任何情况下都不允许敌人踏入他们的国境).
Theorderfromthecommanderwasthatthetroops______(立即开拔去前线).
Martinbeggedhismothertopardonhim,______(保证以后考试不现作弊了).
Theeducationapproachthere_________________(特点是重视考试).
Thearmycommander______astateofemergencyinthatareaafterseveraloutbreaksofsuicidebombs.
随机试题
改错题:改正句子中的错误。经过几次化疗,他的白细胞数量比正常值减少了三倍。
锯齿波触发电路中调节恒流源对电容器的充电电流,可以调节()。
下列哪项不是反映人体生长发育水平的功能指标
A.解表散寒B.温里散寒助阳C.温经散寒通脉D.助膀肾气化E.活血通脉
断面可见多环性同心环状排列的维管束的药材有
我国《合同法》规定,债权人领取提存物的权利,自提存之日起()年内不行使而消灭,提存物扣除提存费用后归国家所有。
设备的装、运、安等各项工作中,不论是采用扒杆起吊或是机械吊装都应注意下列()。
下列关于证券公司自营业务的说法中,正确的有( )。
召公谏厉王弭谤厉王虐,国人谤王。召公告曰:“民不堪命矣!”王怒,得卫巫,使监谤者。以告,则杀之。国人莫敢言,道路以目。王喜,告召公曰:“吾能弭谤矣,乃不敢言。”召公曰:“是障之也。防民之口甚于防川川壅而溃伤人必多民亦如之是故为川者决之使
下列成语使用没有毛病的一项是()。
最新回复
(
0
)