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
Many great inventions are greeted with ridicule and disbelief. The invention of the airplane was no exception. Although many peo
Many great inventions are greeted with ridicule and disbelief. The invention of the airplane was no exception. Although many peo
admin
2010-11-29
66
问题
Many great inventions are greeted with ridicule and disbelief. The invention of the airplane was no exception. Although many people who heard about the first powered flight on December 17,1903, were excited and impressed, others reacted with peals of laughter. The idea of flying an aircraft was repulsive to some people. Such people called Wilbur and Orville Wright, the inventors of the first flying machine, impulsive fools. Negative reactions, however, did not stop the Wrights. Impelled by their desire to succeed, they continued their experiments in aviation.
Orville and Wilbur Wright had always had a compelling interest in aeronautics and mechanics. As young boys they earned money by making and selling kites and mechanical toys. Later, they designed a newspaper-folding machine, built a printing press, and operated a bicycle-repair shop. In 1896, when they read about the death of Otto Lilienthal, the brother’s interest in flight grew into a compulsion.
Lilienthal, a pioneer in hang-gliding, had controlled his gliders by shifting his body in the desired direction. This idea was repellent to the Wright brothers, however, and they searched for more efficient methods to control the balance of airborne vehicles. In 1900 and 1901, the Wrights tested numerous gliders and developed control techniques. The brothers’ inability to obtain enough lift power for the gliders almost led them to abandon their efforts.
After further study, the Wright brothers concluded that the published tables of air pressure on curved surfaces must be wrong. They set up a wind tunnel and began a series of experiments with model wings. Because of their efforts, the old tables were repealed in time and replaced by the first reliable figures for air pressure on curved surfaces. This work, in turn, made it possible for them to design a machine that would fly. In 1903 the Wrights built their first airplane, which cost less than one thousand dollars. They even designed and built their own source of propulsion — a lightweight gasoline engine. When they started the engine on December 17, the airplane pulsated wildly before taking off. The plane managed to stay aloft for twelve seconds, however, and it flew one hundred twenty feet.
By 1905 the Wrights had perfected the first airplane that could turn, circle, and remain airborne for half an hour at a time. Others had flown in balloons or in hang gliders, but the Wright brothers were the first to build a full-size machine that could fly under its own power. As the contributors of one of the most outstanding engineering achievements in history, the Wright brothers are accurately called the fathers of aviation.
The old tables were______and replaced by the first reliable figures for air pressure on curved surfaces.
选项
A、destroyed
B、canceled
C、multiplied
D、discarded
答案
D
解析
细节题。“old tables”是定位关键词,第四段“the old tables were repealed in time and replaced by the first reliable figures for air pressure on curved surfaces”可看出原数据经过新的实验后被修订了。
转载请注明原文地址:https://kaotiyun.com/show/bt1K777K
0
专业英语四级
相关试题推荐
Thefirsttwostagesinthedevelopmentofcivilizedmanwereprobablytheinventionofweaponsandthediscoveryoffire,altho
IsContinuingEdforYou?Continuingeducationisimportantforeveryonenow,inallfields.Almostassoonasyou’vecomp
Somepeoplebelievethatyouhavetobeaspecialkindofpersontosellaproduct.Butalthoughitisclearthatasuccessfuls
Thatinventionofhisentitleshim______aplaceamongthegreatinventors.
JohnD.Rockefeller,______,owned90percentofallAmericanoilrefineries.
Althoughthefirstpartofthebookiseasy,therest______.
Althoughhemadeseveralinventionswhenhewasveryyoung,______hewasthirty.
Althoughthemodellooksgoodonthesurface,itwillnotbearclose______.
随机试题
该病人初步诊断是首选的治疗方法是
由肾分泌的生物活性物质有
对放射治疗不敏感的恶性肿瘤是
揭示公司定价错误的风险程度的比率是()。
根据民事诉讼法的规定,下列说法中哪些是正确的?
召开公司董事会时,如董事长出差在外,会议将由()主持。
假设某基本生产车间甲产品生产工时为1120小时,乙产品生产工时为640小时,本月发生制造费用7216元。按生产工人工时比例法在甲、乙产品之间分配制造费用,甲产品应分配制造费用为()元。
关于前庭器官的叙述,下列哪项不正确
设f(x)在x>0上有定义,且对任意的正实数x,y,f(xy)=xf(y)+yf(x),f’(1)=2,试求f(x).
常规密钥密码体制又称为(1),它是指(2)的密码体制。属于常规密钥密码体制的密码是(3)。采用密钥流序列作为密钥序列的属于(4)。国际数据加密算法IDEA属于(5)。
最新回复
(
0
)