首页
登录
职称英语
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese
游客
2024-04-14
42
管理
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【B1】______, 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【B2】______. It rose awkwardly and vertically into the air from a standing start, hovered a few feet above the ground, went 【B3】______ 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 anticipated that vertical flight transports would carry millions of passengers as do the airliners of today. Such fantastic expectations were not【B4】______.
The helicopter has now become an extremely useful machine. It【B5】______ in military missions, carrying troops, guns and【B6】______ 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【B7】______ 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【B8】______ crews and supplies. Any urgent mission to a hard-to-get-to place is a likely task for a helicopter. Among their other 【B9】______ of use: deliver people across town, fly to and from airports, 【B10】______ rescue work, and aid in the search for missing or wanted persons. [br] 【B7】
选项
答案
advantageous
解析
空格所在句讲直升飞机在各个领域的应用,advantageous意为“有利的”。
转载请注明原文地址:https://tihaiku.com/zcyy/3555427.html
相关试题推荐
[originaltext]Today,ChineseAmericansmakeuplessthan1%oftheU.S.pop
[originaltext]Today,ChineseAmericansmakeuplessthan1%oftheU.S.pop
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
Forcenturiesmendreamedofachievingverticalflight.In400A.D.Chinese
Forcenturiesmendreamedofachievingverticalflight.In400A.D.Chinese
随机试题
Probablyoneofthemostrevolutionaryinnovationsinscienceduringthisce
VALIUMInthe1960s,Valiumwaslaunchedaroundthe
ThelargestcityinCanadaisA、Vancouver.B、Montreal.C、Toronto.D、Ottawa.C多伦多是
巴黎公社文学的最有代表性作家有()A.欧仁·鲍狄埃 B.路易丝·米雪尔 C
下列各项中,属于各级政府编制年度预算草案的依据的为()。A.上级政府对编制本年度
采用不通过血脑屏障显像剂的脑静态放射性核素显像,脑肿瘤的阳性率与下列的关系是A.
女,30岁,婚后5年未孕,痛经3年。平素月经规律,近3年出现经期腹痛,并呈进行性
A公司拟溢价发行附认股权证的公司债券筹资,债券的面值为1000元,期限为5年,票
D
下列属于糖酵解途径关键酶的是A.6-磷酸葡萄糖酶 B.丙酮酸激酶 C.柠檬酸
最新回复
(
0
)