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
考研
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese children played with a fan-like toy that spun upward
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese children played with a fan-like toy that spun upward
admin
2012-08-24
102
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 used: 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
文章第三段指出,人们梦想乘坐直升机上下班,期望它能够像如今的班机一样运载大量乘客。故答案为D。
转载请注明原文地址:https://www.kaotiyun.com/show/rnhi777K
0
在职申硕(同等学力)英语
相关试题推荐
Learningdisabilitiesareverycommon.Theyaffectperhaps10percentofallchildren.Fourtimesasmanyboysasgirlshavelea
Accordingtothepassage,thevolunteers______.Fromthesecondparagraphwecanknowthat______.
In(businessasawhole),thereisacontroversy(asto)whether(arebusinesses)reallyencouragingtheprospectsofgreater(e
Ecotourismismeantto______.Accordingtothepassage,asolutiontothe"ecotourism"problemisto______.
Chinesefarmersaremostlylivingasimpleandthriftylifeasitistoday.
Ascollegeteachers,theyenjoytalkingabouttheirownspecialties.
Woman:MycousinBobisgettingmarriedinCaliforniaandIcan’tdecidewhethertogo.Man:It’salongtrip,butIthinkyo
Atapressconferenceaftertheawardceremony,the18-year-oldgirlspokeinabarely______voice.
Thecountryannouncedthatitwouldhaltnucleartestingthisyearandhopedthatothercountrieswouldtakethesameaction.
MostAmericanmagazinesandnewspapersreserve60percentoftheirpagesforads.TheNewYorkTimesSundayedition【1】maycontai
随机试题
内分泌功能减退性疾病的替代治疗,目前较普遍使用的方法是
心为“五脏六腑之大主”的理论依据是
患者,女性,25岁。左侧头部着地摔伤,曾出现意识丧失。无头痛、呕吐。查体:血压118/72mmHg,脉搏78/分,呼吸19/分。神志清醒,对答切题。左耳有血性液体流出。根据目前患者的情况,最重要的治疗是
脾统血和肝藏血是同摄血液的重要因素。()
贷款合同由于履行过程中监管不力可能产生法律纠纷的做法有()。
一次,你的一位很健谈、很有学识的朋友不请自到,来你家做客,这位朋友穿戴邋遢、坐卧随意。你的妻子(丈夫)是一位爱洁净的人,你朋友的这些举动惹得你的妻子(丈夫)怒形于色。你会()。
在管理策略上,现代人力资源管理属于()的管理。
下面是教师在教授《中国石拱桥》时设计的教学重难点,对此分析错误的是()。教学重点:(1)引导学生把握石拱桥的特征,掌握抓住特征说明事物的方法。(2)品味说明文语言的准确性和严密性。教学难点:以赵州桥、卢沟桥为重点说明中国石拱桥,理解作者的说明
下列情形中,侵犯了公民宪法权利的是()。
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
最新回复
(
0
)