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
Why were the Wright brothers able to succeed in an effort at which so many others had failed? Many explanations have been mentio
Why were the Wright brothers able to succeed in an effort at which so many others had failed? Many explanations have been mentio
admin
2011-02-28
82
问题
Why were the Wright brothers able to succeed in an effort at which so many others had failed? Many explanations have been mentioned, but three reasons are most often cited. First, they were a team. Both men worked congenially and cooperatively, talked incessantly about the possibility of manned flight, and served as a conscious source of inspiration and encouragement to each other.
Both were glider pilots. Unlike some other engineers who experimented with the theories of flight, they experienced the practical aspects of aerodynamics by building and flying in kites and gliders. They had realized from their experiments that the most serious challenge in manned flight would be stabilizing and maneuvering the aircraft once it was airborne. While others concentrated their efforts on the problem of achieving lift for take-off, they were focusing on developing a three- axis control for guiding their aircraft.
In addition, the Wright brothers had designed more effective wings for the airplane than had been previously engineered. Using a wind tunnel, they tested more than two hundred different wing designs, recording the effects of slight variations in shape on the pressure of air on the wings. The data from these experiments allowed the Wright brothers to construct a superior’ wing for their aircraft.
In spite of these advantages, however, the Wright brothers might not have succeeded had they not been born at precisely the opportune moment in history. Attempts to achieve manned flight in the early nineteenth century were doomed because the steam engines that powered the aircrafts were so heavy in proportion to the power that they produced. But by the end of the nineteenth century, when the brothers were experimenting with engineering options, a relatively light internal combustion engine had already been invented, and they were able to bring the ratio of weight to power within acceptable limits for flight.
Why does the author suggest that the experiments with the wind tunnel were important?
选项
A、Because they allowed the Wright brothers to decrease the weight of their airplane.
B、Because they resulted in a three-axis control for their airplane.
C、Because they were important in the refinement of the wings for their airplane.
D、Because they used the data to improve the engine for their airplane.
答案
C
解析
从文章第三段可以推断,目的在于找出最佳的机翼形状。
转载请注明原文地址:https://kaotiyun.com/show/6Wtd777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
Schoolsofeducationhavelongbeenobjectsofcriticism.FromJamesKoorner’s1963book,TheMiseducationofAmerica’sTeachers
Schoolsofeducationhavelongbeenobjectsofcriticism.FromJamesKoerner’s1963book,TheMiseducationofAmerica’sTeachers
Parentsnowhaveapopularbeliefthatschoolsarenolongerinterestedinspelling.NoschoolIhavetaughtinhaseverignored
Parentsnowhaveapopularbeliefthatschoolsarenolongerinterestedinspelling.NoschoolIhavetaughtinhaseverignored
SlaveryhasplayedasignificantroleinthehistoryoftheU.S.ItexistedinalltheEnglishmainlandcoloniesandmostofth
SlaveryhasplayedasignificantroleinthehistoryoftheU.S.ItexistedinalltheEnglishmainlandcoloniesandmostofth
Whydidthedrivermentionhiswife’scousin’shusband?
Theexamplestheauthormentionsinthefirstparagraphisto______.WhatisthebestAprilfool’strickintheauthor’sopin
随机试题
()是小组动力的关键。
以下说法不正确的是
片剂生产中制粒的目的是
最易引起原发性肝癌的疾病是()
某工程合同价为1000万元,合同约定:物价变化时合同价款调整采用价格指数法,其中固定要素比例为0.3,调价要素为人工费、钢材、水泥三类,分别占合同价的比例为0.2、0.15、0.35,结算时价格指数分别增长了20%、15%、25%,则该工程实际价款的变化值
企业追加筹资的成本是()。
某系统进程P1在时刻t开始执行,所需执行时间是5秒。进程P2在时刻t+2秒开始执行,所需执行时间是2秒。随后无其他进程进入系统。如果进程调度算法为时间片轮转(RR),时间片大小为1秒且调度开销忽略不计,那么()。
树是结点的集合,它的根结点的数目是( )。
Hetakes______attheslightestcriticism.
Bynomeans__________readytoquitherstudy.
最新回复
(
0
)