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
专升本
For centuries men dreamed of achieving vertical flight. In 400 A. D. Chinese children played with a fan-like toy that spun upwar
For centuries men dreamed of achieving vertical flight. In 400 A. D. Chinese children played with a fan-like toy that spun upwar
admin
2014-06-25
46
问题
For centuries men dreamed of achieving vertical flight. In 400 A. D. Chinese children played with a fan-like toy that spun upwards and fell back to earth as rotation ceased. Leonardo da Vinci conceive the first mechanical apparatus, called a "Helix," which could carry man straight up, but was only a design and was never tested.
The ancient-dream was finally realized in 1940 when a Russian engineer piloted a strange looking craft of steel tubing with a rotating fan on top. It rose awkwardly and vertically into the air from a standing start, hovered a few feet above the ground, went sideways and backwards, and then settled back to earth. The vehicle was called a helicopter.
Imaginations were fired. Men dreamed of going to work in their own personal helicopters. People anticipate that vertical flight transports would carry millions of passengers as do the airliners of today. Such fantastic expectations were not fulfilled.
The helicopter has now become an extremely useful machine. It excels in military missions, carrying troops, guns and strategic instruments where other aircraft cannot go. Corporations use them as airborne offices, many metropolitan areas use them in police work, construction and logging companies employ them in various advantageous ways, engineers use them for site selection and surveying, and oil companies use them as the best way to make offshore and remote work stations accessible to crews and supplies. Any urgent mission to a hard-to-get-to place is a likely task for a helicopter. Among their other multitude of uses: deliver people across town, fly to and from airports, assist in rescue work, and aid in the search for missing or wanted persons.
What is said about the development of the helicopter?
选项
A、Helicopters have only been worked on by man since 1940.
B、Chinese children were the first to achieve flight in helicopters.
C、Helicopters were considered more dangerous than the early airplanes.
D、Some people thought they would become widely used by average individuals.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/HXUC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
Manychangesaretakingplacein"foodstyle"intheUnitedStates.TheUnitedStatesistraditionallyfamous【36】itsverysolid
WhatistheWritingLabandwhyshouldIuseit?TheWritingLabisafreeservicewhereallstudentsatPurdueUniversityc
ModernAmericanmusicisrichinitsvarietyofforms,styles,andinstruments.Acompleteencyclopedia(百科全书)ofAmericanmusic
Thecompanyrequiresthateverystaffmember______abletouseacomputer.
(英语专业学生做)Ineverycultivatedlanguagetherearetwogreatclassesofwordswhich,takentogether,comprisethewholevocabu
Haveyou【56】askedyourselfwhychildrengotoschool?Youwillprobablysaythattheygo【57】languages,mathematics,history,sci
Onceitwasconsideredgoodtokeepthecarengineidlingaminuteortwofollowingcoldstarts.Today,withmoderntechnology,
MillionsofpeoplepassthroughthegatesofDisney’sentertainmentparksinCalifornia,FloridaandJapaneachyear.Whatmakes
Rockmusicusually______theyoungpeopleinmostcountries.
Halloweenisaholiday,whichcomesattheendofOctober.Itwidelycelebrated,withdifferentnames,inmanycountries.Althou
随机试题
以下不是通缉令使用的必备条件的是()
在中国现代文学史上,全面系统介绍西方美学理论的第一人是________。
下列与肾关系密切的是
A.头低足高位,头偏向一侧B.去枕平卧位C.平卧位,头偏向一侧D.端坐位E.患侧卧位支气管哮喘发作患者
免疫性不孕( )垂体功能障碍导致不孕( )
.女,35岁。l周前,曾因咳嗽,低热就诊,诊断为上呼吸道感染,近两天来发现颈部疼痛,波及到耳、颞、枕部,查体:甲状腺弥漫性肿大,质硬,压痛,体温38℃,ESR20mm/h,BMR+20%,碘吸收率2小时5%,24小时20%,甲状腺穿刺可见白细胞浸润和吞有胶
从原则上来讲,事故调查组应该自事故发生()日内提交事故调查报告。
背景某机场施工单位在场道土石方施工中,发生了以下情况:(1)选用了4m3的挖掘机,载重12t的自卸汽车;(2)石方爆破的承包单位用敷炮的方式处理大块;(3)在填方施工时,对填方土的含水量没有严格控制。能否用敷炮的方式处理大块石头?
Hewas______onlybyhiswishtohelpme,andexpectednothinginreturn.
Youngashewas,hewasequaltohetask.
最新回复
(
0
)