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
21
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..
【21】
选项
A、on
B、by
C、for
D、in
答案
D
解析
转载请注明原文地址:https://jikaoti.com/ti/ESisFFFM
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
RecentsurveysshowthatJapaneseyouthhavebecomea"MeGeneration"thatrejectstraditionalvalues."Around1980manyJap
What’stheaverageincreaseperyearofforeignstudentpopulationintheperiodbetween1985and1990intermsofpercentage?
A=BOOK1B=BOOK2C=BOOK3D=BOOK4Whichbook(s)say(s)that...theclimateaffectsthefuturesustainableagricultural
A=BOOK1B=BOOK2C=BOOK3D=BOOK4Whichbook(s)say(s)that...theclimateaffectsthefuturesustainableagricultural
Whichpassage(s)say(s)that….adultsputtoomuchemphasisonchildren’sintellectualdevelopment?
InhisbookMr.Brooksdescribestheroboticspresentand________.
InhisbookMr.Brooksdescribestheroboticspresentand________.
TheissueofonlineprivacyintheInternetagefoundnewurgencyfollowingtheSept.11terroristattacks,sparkingdebateover
Whatdoesthespeakersuggestthatthestudentsshoulddoduringtheterm?
随机试题
"生痰之源"指的是
某日,王某和李某共同串通抢劫路人周某的钱财(价值1万元),二人共同实施抢劫,情节相同。但法院审理此案时,考虑到王某是县政府副县长的儿子,因此判王某抢劫罪,执行3年有期徒刑,而判李某抢劫罪,执行5年有期徒刑。该法院的做法违背了下列哪项原则?
下列关于热空气幕的送风温度的叙述,符合规定的是()。
商业票据的背书人对票据不负有连带责任。()
Writeanessaybasedonthefollowingtable.Inyourwriting,youshould1)interpretthetable,and2)giveyourcomments.
下列条目中,哪些是当SQL语句嵌入到主语言时要解决的问题Ⅰ.区分SQL语句与主语言语句Ⅱ.数据库工作单元和程序工作单元之间的通信Ⅲ.协调SQL语句与主语言语句处理记录的不同方式
Asoneworkswithcolorinapracticalorexperimentalway,oneisimpressedbytwoapparentlyunrelatedfacts.Colorasseenis
Sofar,only14countriesintheworldhavelawsonthebooksspecificallygivinghomosexualcouplestherighttoadoptchildren
Inthesentence"Thisbeautifulvillageremainsunknowntotherestoftheworld",theitalicizedwordis
曲棍球()滑雪自行车()手球
最新回复
(
0
)