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 1820’s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines bu
By the 1820’s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines bu
admin
2010-07-06
15
问题
By the 1820’s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines built in the West (Pittsburgh, Cincinnati, or Louisville), and of a distinctive western design specially suited to western needs. The first steam engines 【21】______ practical use in England and the United States were 【22】______ low-pressure design. This was the type first 【23】______ by James Watt, then manufactured by the firm of Boulton and Watt. Steam was 【24】______ in a large, double-acting vertical cylinder, but the steam reached only a few pounds of pressure per square inch. It was low-pressure engines of this type that 【25】______ first introduced into the United States by Robert Fulton. He 【26】______ such a Boulton and Watt engine from England to run the Clermont. But this type of engine was ,expensive and complicated, 【27】______ many precision-fitted moving parts.
The engine that became standard on western steamboats was of a different and 【28】______ design. It was the work primarily of an unsung hero of American industrial progress, Oliver Evans (1755-1819), the 【29】______ son of a Delaware farmer. Evans early became 【30】______ by the possibilities of mechanized production and steam power. As early as 1802 he 【31】______ a stationary steam engine of high-pressure design in his mill. Engines of this type were not 【32】______ , but before Evans they were generally considered 【33】______ and dangerous. Within a decade the high-pressure engine, the new type, had become standard on western waters. Critics 【34】______ of western conditions often attacked it as wasteful and dangerous.
But people who really knew the Ohio, the Missouri, and the Mississippi 【35】______ , with good reasons, that it was the only engine for them. In 【36】______ western rivers the weight of vessel and engine 【37】______ important; a heavy engine added to the problem of navigation. The high-pressure engine was 【38】______ lighter in proportion to horsepower, and, with less than half as many moving parts, was much easier and cheaper to repair. The main advantages of low-pressure engines were safe operation and 【39】______ of fuel consumption, 【40】______ of which meant much in the West..
【29】
选项
A、educating
B、self-educating
C、education
D、self-educated
答案
D
解析
转载请注明原文地址:https://jikaoti.com/ti/aSisFFFM
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
RecentsurveysshowthatJapaneseyouthhavebecomea"MeGeneration"thatrejectstraditionalvalues."Around1980manyJap
Somepeopleclaimthatstayinginaplaceallone’slifeisgoodforone’sgrowth,whileothersdisagreewiththeview,andth
Inrecentyears,therehasbeenanincreasingawarenessoftheinadequaciesofthejudicialsystemintheUnitedStates.Costsa
Whichpassage(s)say(s)that….adultsputtoomuchemphasisonchildren’sintellectualdevelopment?
Whichpassage(s)say(s)that….adultsputtoomuchemphasisonchildren’sintellectualdevelopment?
"Junkscience"ishowElliotMorley,Britain’sministerresponsibleforgeneticallymodifiedfarming,describesstudiesthatcla
WhichofthefollowingistrueaboutfathersinSweden?
InhisbookMr.Brooksdescribestheroboticspresentand________.
InhisbookMr.Brooksdescribestheroboticspresentand________.
Whichcontinentwherechildrenaretaughttobesilentinfrontofeldersismentioned?
随机试题
羁束行政行为
能对人的工作与学习产生实际效果的兴趣品质是()。
全面建设社会主义现代化国家、实现中华民族伟大复兴的重要法宝是()
酒渣鼻最常见的发病部位为
华昌有限公司有8个股东,麻某为董事长。2013年5月,公司经股东会决议,决定变更为股份公司,由公司全体股东作为发起人,发起设立华昌股份公司。下列哪些选项是正确的?(2013年卷三69题,多选)
根据《堤防工程施工规范》SL260—98,堤防工程施工严禁在堤身两侧设计规定的()内取土。
自然社区,即人类在生产和生活中自然形成的聚落,是非人为的、人们在长期生活中自然形成、共生共存的社会地理空间。其特征不包括()。
在下列存储结构中,数据结构中元素的存储地址与其关键字之间存在某种映射关系的是()。
Advancingagemeanslosingyourhair,yourwaistlineandyourmemory,right?DanaDenisisjust40yearsold,but【C1】______she’s
Whenisadriverlikelytohaveasleep-relatedaccidentaccordingtoresearchers?
最新回复
(
0
)