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 1820s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines bui
By the 1820s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines bui
admin
2012-10-23
57
问题
By the 1820s 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 in practical use in England and the United States were of low-pressure design. This was the type first developed by James Watt, then manufactured’ by the firm of Boulton and Watt. Steam was accumulated 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 were first introduced into the United States by Robert Fulton. He imported such a Boulton and Watt engine from England to run the Clermont. But this type of engine was expensive and complicated, requiring many precision-fitted moving parts. The engine that became standard on western steamboats was of a different and novel design. It was the work primarily of an unsung hero of American industrial progress.
Oliver Evans (1755—1819) was the self-educated son of a Delaware farmer. Evans early became obsessed by the possibilities of mechanized production and steam power. As early as 1802 he was using a stationary steam engine of high-pressure design in his mill. Engines of this type were not unknown, but before Evans they were generally considered impractical and dangerous. Within a decade the high-pressure engine, the new type had become standard on western waters. Critics ignorant of western conditions often attacked it as wasteful and dangerous. But people who really knew the Ohio, the Missouri, and the Mississippi insisted, with good reasons, that it was the only engine for them. In shallow western rivers the weight of vessel and engine was important; a heavy engine added to the problem of navigation. The high-pressure engine was far 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 economy of fuel consumption, neither of which meant much in the West. (354 words)
Which of the following points was made by the critics of high-pressure engines?
选项
A、Having more moving parts.
B、Not powerful enough for western waters.
C、Fuel consuming.
D、Too heavy.
答案
C
解析
第二段第六句中的“wasteful”就是“费油的”之意。
转载请注明原文地址:https://kaotiyun.com/show/wQ9O777K
0
考博英语
相关试题推荐
Ofthegreatvarietyofopinionsconcerning"marriageformoney",thefollowingthreeareimportantwithreferencetothedevel
Mostofusgothroughlifeadding______toknowledge,polishingaconcepthereorthere,doinganexperiment,contributingafew
Doctorshavelongknownthatlungcancer,whichkills160,000Americanseachyear,takesaheaviertollamongblackAmericans,
Beforethemid-nineteenthcentury,peopleintheUnitedStatesatemostfoodsonlyinseason.Drying,smoking,andsaltingcould
71.Christianityisthelong-exitingreligionmainlyfoundintheWesternworld,inwhichitisGodthatcreateseverythingint
AIDSiscausinggreatpublicconcernbecausethe______fataldiseasehitsprimarilyyoungpeople.
Researchershavediscoveredinrecentyearsthatthereisasystemtotheactionsalmostasconsistentand______aslanguage.
Thejudge’sdecision______Montez’shopesofreceivingareducedprisonsentence.
Theaccommodationwascheap,butthefoodwasvery______.
Oneofthebasiccharacteristicsofcapitalismistheprivateownershipofthemajormeansofproduction-capital.Theownership
随机试题
泥泞迟子建北方的初春是肮脏的,这肮脏当然源自我们曾经热烈赞美过的纯洁无瑕的雪。在北方漫长的冬季里,寒冷催生了一场又一场的
A.肌张力低下B.肌张力增高C.原始反射D.立直反射E.平衡反射婴儿特有的一过性反射是
辨别寒热真假时要注意,真象常出现于()
甲是A国驻B国大使馆的商务参赞,乙是C国驻B国大使馆的随员。甲与B国人丙发生债务纠纷。甲向B国法院对丙提起民事诉讼,丙对甲就同一债务关系提起反诉,并要求乙作为证人出庭作证。根据国际法规则,下列哪个判断是正确的?()
建设单位应当自建设工程竣工验收合格之日起()日内,将竣工验收报告和规划、公安消防、环保部门出具的认可文件或者准许使用文件报建设行政主管部门或者其人有关部门备案。
某机电安装工程公司承包了某工业厂房的管道安装工程。在施工过程中,施工项目部特别重视该工程的施工方法和操作工艺,对每一工序都制订了具体的控制方法。该管道工程属于高温、高压管道工程,为此,施工总承包企业在选择管道时主要从耐高强、耐热、耐腐蚀、高密封和防
燃气轮机中常用的液体燃料有()等。
中国有文字记载的最早的帝王巡游是在公元前()左右。
《中华人民共和国义务教育法》是我国教育的宪法。()
Whereprobablyarethespeakers?
最新回复
(
0
)