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
60
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
TheresearchalsoraisesthepossibilitythatyoungerpeopleA(treat)successfullyforcancerB(withchemotherapy)maybeC(subj
Theonlywayhecoulddoit-andby"it"hemeansachievingtheleveloffameenjoyedbyMartin,whoissofamousthathisinfant
Governmentisabasicmeansoforderinghumanrelations.【C1】______itscitizens,governmentgenerally【C2】______certainwell-organ
WhatHighTechHasWroughtTheunprecedentedU.Seconomicboomofthelasthalfofthe1990swaspropelledbyinvestmentin
【56】Astateuniversitypresidentwasarrestedtodayandchargedwithimpersonateapoliceofficerbecause,theauthoritiessay,
Beforetheconstructionoftheroad,itwasprohibitivelyexpensivetotransportanyfursorfruitsacrossthemountains.
Justiceinsocietymustincludebothafairtrialtotheaccusedandtheselectionofanappropriatepunishmentforthoseproven
Oneofthebasiccharacteristicsofcapitalismistheprivateownershipofthemajormeansofproduction-capital.Theownership
A、contractB、peaceC、ceasefireD、treatyC本题考核的知识点是:对应成分分析一and对应。and前后性质相同,and后面是agreedtoavoteonthefutureoftheterritory,所
随机试题
患儿,男,9个月。先天性左侧完全性唇腭裂。根据唇腭裂序列治疗的原则,腭裂修复的年龄应在
阿托品抗休克作用的机制是()
【背景资料】某施工单位承接了一段长30km的沥青混凝土路面施工改建任务,路面结构为:6cm厚AC一20下面层摊铺、5cm厚AC—16中面层摊铺、4cm厚SBS改性沥青SMA上面层摊铺。其中基层采用厂拌水泥稳定碎石,基层厚40cm,分两层施工。底基
按照理论推测和以往的投资实践,股票投资的风险大于股票基金,股票基金投资的风险又大于债券。()
下列属于金融市场客体的是()。
下列各项中,不应在财务报告附注中进行披露的是()。
下列各项中,符合我国《仲裁法》规定的有()。
在Excel工作表中每个工作簿只能包含3张工作表。()
不可能所有的错误都能避免。以下哪项断定的含义,与上述断定最为接近?
打开一个窗体,要通过选择窗体的数据输入与窗体方式,限制窗体所显示的记录,应使用的宏操作命令是()。
最新回复
(
0
)